Kristin Bertilson was just 13 when her family decided to move from their large Victorian house in Maryland to a much smaller place in Oregon. As the eldest of four girls -- and the one born with what she calls "the organizing gene" -- she pitched in to downsize the family's seemingly countless possessions.

"It was a huge job because all we could take along was what fit in our two cars plus my grandfather's small trailer," Bertilson recalls.

The experience taught her many lessons she's applied hundreds of times after starting her own small firm, Queen B Organizing. Her company helps clients purge household accumulations, usually in preparation for a home sale and move. It can be an emotional and daunting experience, but it's increasingly a necessary one.

Mark Nash, a real estate broker and author of "1001 Tips for Buying and Selling a Home," urges home sellers to undertake the purging process as soon as they know they'll be moving. That's because a de-cluttered home is much more appealing to prospective buyers.

"You'll have to pack up anyway when you move. So why not do your purging and packing before you list your property rather than right before you move?" Nash says.

Here are a few pointers for downsizers:

-- Do a preliminary inventory of your accumulations.

Some downsizers try to grapple with the de-cluttering process without a plan. But those who do a preliminary inventory of their problem before seeking to solve it are more efficient, says Dorcas Helfant, a former president of the National Association of Realtors (www.realtor.org).

"Sellers who have a room-by-room picture of all their possessions can make faster decisions about how to streamline it all," she says.

The listing agent you've chosen to sell your home can assist in assessing which items should be removed from your place before it's shown. These will likely include some bulky furnishings.

"A house filled with furniture can look a lot smaller than it truly is. And no one wants to buy a house that seems crowded," Helfant says.

-- Create an action plan.

Nash says those who are most efficient at de-cluttering follow a step-by-step action plan.

As a beginning step, he recommends you plot the space in your new property before deciding on the items you can take with you. This assumes, obviously, that you've already selected your next home.

A few years back, Nash left a 3,200-square-foot bungalow for a 760-square-foot condo -- requiring him to drastically reduce his total belongings. To gain a more precise estimate, he bought graph paper and plotted the layout and storage space available at his new residence.

"The drawing allowed me to plan a place for everything I expected to take with me, down to my bike and favorite clothes. That made it clear which things would be impossible to keep," he says.

-- Take a systematic approach to sorting.

During their years in a property, many homeowners unwittingly acquire a large array of similar items. Early in the purging process, Nash suggests that sellers sort like items to determine what's superfluous and what isn't.

"I'm talking about all that stuff you went to the store to buy because you didn't know you already owned it. After you see all the rampant duplication, it's easier to cut out extras," he says.

Once you have the like items in each room categorized, use what Nash calls the "three-box system" to cull through them efficiently. One box should be labeled "keep," a second "give away or sell," and a third, "I don't know."

To hasten the process, immediately make arrangements to have your "give away or sell" items carted off. This allows you to create more space to sort through possessions from the "I don't know" box that will require more consideration.

-- Make liberal use of your trashcans.

For home sellers who must clear through a house full of possessions in a short period of time, trashcans become essential gear.

"It may not be environmentally friendly, but it can be one of the best available solutions to simply throw a lot of things away. 'Out of sight, out of mind' is the mantra you have to use," Nash says.

How do you decide what to toss?

When going through piles of clothing, Nash recommends this rule of thumb: "If you haven't worn the item for a year, throw it out." He also recommends you reconsider keeping old gizmos you're no longer using.

"Most all that dated technology should go into responsible recycling. There's no point in keeping technology that's obsolete and has undoubtedly lost all its value," he says.

-- Bring in your "support staff."

Even well-organized downsizers find the purging process arduous. Because of that, Nash says it's ideal to seek the assistance of friends or relatives.

If you don't know anyone you're comfortable recruiting, Nash says you can find reasonably priced help -- perhaps from a high school or college student -- through "help wanted" advertising. Or you might consider going online to find a professional organizer in your area. One group that offers referrals is The National Association of Professional Organizers (www.napo.net).

"Whatever it takes to motivate and organize you is what you've got to do," Nash says.

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)

Mary McCall has sold homes since 1987, and with each year that passes she encounters more would-be sellers who resist the need to make vitally important pre-sale improvements to their front yard.

"A house that looks uninviting from the street won't capture enough buyer interest to get showings. But a house that looks fabulous from the street -- with manicured flower beds, blooming perennials and fresh mulch -- can command tremendous buyer interest," says McCall, president of the Council of Residential Specialists (www.crs.com).

"If you have weeds growing everywhere and vines climbing out of your gutters, your house will take longer to sell and for less money. That's because buyers who see an out-of-control yard assume the mechanical systems inside the house have also been neglected," McCall says.

As she notes, bushes and trees that grow near a property shouldn't rise above the bottom of window frames. And lawns should be kept weeded and fertilized, with all plants near the property kept trim and healthy.

Failing to tame an out-of-control yard is one common error many home sellers make. Here are a few others:

-- Mistake No. 2: Trying to show your home with a grimy interior.

Sid Davis, a real estate broker and author of "A Survival Guide to Selling a Home," says that trying to sell a home that's unclean is a huge mistake.

The problem is that buyers view other people's dirt and mess as far more objectionable than their own poor housekeeping.

"Those dirty dishes in the sink and the piles of dirty laundry in your teenagers' bedrooms are really a huge turnoff for buyers," Davis says.

As with yard work, McCall says fewer homeowners now have the time or willpower to tackle in-depth housecleaning chores. But when attempting to sell a property, cleanliness is paramount.

"Everybody wants a fresh start when they move. That's why buyers love a super-clean place. If a house they step into is dirty, they'll immediately turn around and walk right out," she says.

Unless their homes are immaculate, McCall recommends that sellers pay for in-depth cleaning. And she suggests that those planning to hire a professional cleaning service, as opposed to an individual, check customer reviews on a website that tracks service providers, such as Angie's List (www.angieslist.com).

-- Mistake No. 3: Rebuffing your listing agent's advice on fix-ups.

As real estate experts point out, sellers benefit when they receive a critique of their property well before it goes up for sale. That way they have time to make sure that all important repairs and upgrades are done before buyers troop through.

But Davis contends that too many agents "fear giving sellers the straight truth." He says some worry their candid remarks about a property could cost them the chance to obtain or retain the sellers' business.

But home sellers who are savvy welcome constructive criticism, he says.

"Why not hand the agent a room-by-room checklist on which they can itemize the improvements you need to make to maximize the sale? And leave space on the checklist for changes to your yard," Davis says.

Obviously, it's not enough to merely solicit feedback. You'll also need to go down the checklist and make the suggested changes, whether these involve replacing stained carpeting or fixing leaky faucets.

-- Mistake No. 4: Listening to pricing suggestions from know-it-all neighbors.

As soon as word spreads that you're planning to sell, the odds are neighbors will begin offering advice on pricing.

"Neighbors believe they'll benefit if you price high because they think that will push up local home values," Davis says.

But neighbors' views on pricing are often based solely on wishful thinking or the rumored sale prices for other homes that have sold. That's why Davis recommends you ignore their suggestions and set your asking price only after sitting down with your agent to do a systematic review of recent sales in your area.

"If you want another opinion, call in an appraiser. That's much better than relying on gossip," Davis says.

With rare exceptions, he urges sellers to avoid the common error of trying to "test the market" with a list price higher than what similar properties in the area have fetched. That's because an over-market asking price usually hurts the reputation of a home and yields less in the long run.

"It's one of the great ironies of real estate that greedy sellers are usually shortchanged in the end," he says.

-- Mistake No. 5: Hanging around during showings.

Real estate agents almost always advise their clients to disappear when their property is shown. But some sellers believe they know better and insist on staying around.

"These sellers don't like strangers walking through their home, which they find unsettling. They worry something bad will happen to the property if they're not there to protect it," says Fred Meyer, a longtime broker who sells real estate around Harvard University.

But, as Meyer explains, it's tough for buyers to bond with a property if they must muffle their comments to avoid offending the owners.

"Buyers need to be able to say out loud the negatives about a house so they can figure out how they'd address them. It takes a lot of energy not to say what you really think," Meyer says.

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)

In most areas, a real estate recovery is underway, puncturing the fierce buyers' market that let purchasers dictate the terms and conditions of transactions. But, surprisingly, some sellers have yet to get the message.

That's according to Dorcas Helfant, a seasoned real estate broker who co-owns seven realty offices. She says some sellers, admittedly a minority, are still so nervous about their prospects that they overspend on pre-sale upgrades.

To illustrate, she tells the story of a client who fretted so much about selling his upscale property that he planned to spend $80,000 on a kitchen overhaul.

"Not only was he spending way too much, but he was planning changes that would make it harder, not easier, to market his home," Helfant says.

What the executive had in mind was to give his ordinary kitchen an Italian villa look with ornate cabinets of exotic wood and fanciful fixtures.

"It was a totally personalized vision. But buyers don't want your personal taste. They want a blank canvas where they can fill in their own vision," she says.

It took a while, but Helfant eventually dissuaded her client from his plan. Instead, he did a minor kitchen redo involving classic white cabinets with sleek, clean lines --the sort of interior most purchasers prefer. And after his modest investment, his house sold promptly for the full asking price.

Before doing any pre-sale upgrades, Helfant urges sellers to review their plans to make sure they're both appropriate and worthy of the cost. For advice on pre-sale upgrades, she recommends that sellers visit the Houselogic website: www.houselogic.com.

Here are a few pointers for sellers:

-- Look to real estate specialists for guidance.

To find a happy medium for spending on pre-sale improvements, Helfant suggests that sellers ask one or more local real estate agents to drop by their place and provide a checklist of changes that would be cost-effective.

"Don't be timid about seeking advice from professionals -- even before you choose the person you want to take your listing," she says.

An increasing number of agents now recommend that sellers seek the help of a "home stager," someone skilled in the art of making a property look appealing to potential buyers. They review the home's current furnishings, remove excess pieces and rearrange the remaining ones. They may also lend the sellers additional furnishings to improve the look of the home while it's on the market.

Christian Salinas, a home stager in Washington, D.C. (www.stagingdesigndc.com), says it needn't cost a fortune to dramatically improve the appearance of a home through staging. And although the full services of a stager --including the use of inventory items -- can exceed $1,000, he says a less expensive alternative is to hire a stager for a brief consultation and then carry out the stager's suggestions.

-- Seriously question if a pre-sale addition is warranted.

If you have a small house to sell, would it be a good idea to add another bedroom or two to make it more inviting to buyers with children?

"The answer is an unequivocal 'no,' unless you're willing to throw money away that you'll never get back," says Sid Davis, a real estate broker and author of "A Survival Guide to Selling a Home."

With rare exceptions, Davis says homeowners who attempt a pre-sale addition typically recoup no more than 50 percent of their expenses, due to the high cost of expanding an existing home.

Perhaps you believe you could save on an addition by avoiding the architect's fees. But Davis says this, too, would be a mistake.

"Without an architect for your design work, your new room could look funny and fail to blend with the rest of the place. That could torpedo your whole project and prove a costly error. It would be better to dump the addition plan altogether," Davis says.

-- Don't top neighborhood standards with your upgrades.

Real estate specialists agree that when it comes to pre-sale improvements, your kitchen should be a high priority. That's because a kitchen that looks uninviting is a major turnoff to buyers, who could reject your place on that basis alone.

But Helfant says that concentrating on the kitchen doesn't mean you must spend a sizeable sum there. And she stresses that no one needs to exceed neighborhood standards on kitchen improvements.

"For instance, if your countertops look worn and need replacing, you don't need granite -- assuming all your neighbors still have linoleum," she says.

How can you size up neighborhood standards? One way is to seek the counsel of a listing agent who's thoroughly familiar with your neighborhood and has toured many homes there.

"You can also stop by open houses to get a feel for the features of your neighbors' homes," Helfant says.

-- Never forget the street view of your property.

There are more reasons than ever for sellers to focus on the external appearance of their property. The major one is that virtually all buyers now screen properties online or through print publications before deciding which ones to visit. And the front view of your property is the most important image they'll see.

"The landscaping in your front yard must look absolutely amazing," Helfant says.

The good news is that you don't need an expensive landscaping company to make your yard look much better, assuming you're handy with yard gear or know someone who is.

"You can do wonders with ordinary trimming, edging, cutting and mulching, along with the addition of some blooming flowers. The key is to just get the work done, always remembering that your yard is the frame around your home," Helfant says.

(To contact Ellen James Martin, email her at ellenjamesmartin@gmail.com.)