In the 1980s police drama "Hill Street Blues," Sgt. Phil Esterhaus would begin the show with a warning to the assembled officers at the morning roll call. "Let's be careful out there," he cautioned.

Nowadays, that same admonition should be aimed at America's homeowners. According to the Consumer Federation of America (CFA), four of the 10 most popular scams currently making the rounds revolve around how and where we live.

Ruses involving automobiles topped the list. But ripoffs concerning home improvements and construction were the second most common complaints cited by consumer agencies last year, followed by utilities (ranked no. 3), landlord/tenant issues (7) and household goods (8).

Thirty-three consumer agencies from 21 states participated in the annual CFA survey, which was conducted in partnership with the National American Consumer Protection Investigators. In all, these agencies fielded some 200,000 complaints in 2015.

When it comes to home improvements -- which were among the worst complaints based on the sheer number of them, plus the money involved and the impact on consumers -- gripes were all over the ballpark. Here are some tips from the CFA report for dealing with contractors:

-- Before you hire anyone, ask your state or local consumer protection agency whether they need to be licensed or registered to ensure they are competent to do the work. Then ask to see their license.

-- Obtain several estimates, making sure that they cover the exact same things, and get references from their most immediate past customers -- not the customers they pick out. Beware of contractors who try to scare you into thinking the work must be done immediately. If it's truly an emergency, then the step above increases in importance.

-- Obtain a written contract that describes, in full, the work to be done and sets a payment schedule. The CFA says payments should be proportionate to the amount of work that has been completed and the supplies that have to be ordered.

-- Give only a small deposit. Some states set a ceiling on the down payment contractors can take -- a third of the total amount, for example. The contractor who asks for more is undercapitalized, meaning he needs your money to buy supplies or to finish his last job. And never pay the full amount until the job is finished to your satisfaction.

-- Steer clear, the report warns, of any itinerant contractors who show up at your door uninvited. "These are scammers whose only interest is to take your money. If they do any work at all, it is shoddy and incomplete," the report says. If door-to-door sellers must be licensed, ask to see proof they have complied. Beware of phony licenses; read them carefully.

Now that you've vetted your contractor, here are some tips for avoiding scams from the other categories in the CFA survey: utilities, household goods and landlords.

Phonies who say they are calling from the Internal Revenue Service aren't the only imposters making the rounds these days. So are charlatans claiming to work for public utilities, threatening to cut off your service if your "overdue bill" isn't immediately paid by credit card over the phone.

If you are on the receiving end of such a call, the CFA advises, hang up and call the company directly to verify your account balance. Report the scam not just to the company, but also your local consumer agency, so it can issue a public warning.

When it comes to big-ticket household goods, pay with a credit card so you can dispute the charge if an item is never delivered or it doesn't conform to claims made by the seller. Save all advertisements, receipts, warranties and other documents for your records.

Warranties are especially important. Most manufacturers offer them because they show consumers they stand behind their products. If there is a warranty, you have the right to see it before you make the purchase. But realize warranties vary widely in terms of length, what exactly is covered and what you must do to get the item repaired or replaced.

Disputes with landlords are always nettlesome. Read your lease carefully before signing, and obtain a copy so you'll know what you can and cannot do on the property.

Landlords are required in many states to make sure their properties meet certain health and safety standards. If you call about a problem, follow up with a letter and photos and keep copies for your records. Depending on the severity of the trouble, there could be limits on the time your landlord has to respond. Your consumer agency can tell you about your rights and how to enforce them if the landlord doesn't cooperate.

The toughest challenge facing people looking to purchase a home this year is other buyers. And the competition is especially rough among first-time buyers who are searching for houses in the lowest price ranges.

It doesn't help that the inventory of decent houses for sale is depleted. But when something affordable and in good condition comes along, investors with cash in hand often are first in line to seal the deal before would-be owner-occupants even find out about the place.

There's no sure way to beat your competition to the punch. According to a recent survey of agents affiliated with Redfin, some buyers have resorted to making offers on more than one house at a time to boost their chances of getting one of their offers accepted.

Here are some other ideas on how to come in first:

-- Get yourself in the hip pocket of a top producing agent in your favorite area of town. Agents are the first to know when a property comes on the market, and if they know they already have a buyer in hand, they may not even put it into the multiple listing service for the world to see. So tell the agent what you are looking for and make sure he or she understands you are not just out there kicking tires.

-- Cash usually wins out, so maybe you can make yourself an all-cash buyer by borrowing the entire purchase price from the Bank of Mom and Dad. Then, after you close on the house, you can finance the place and pay your folks back.

-- Absent that, try to level the playing field by going as far as you possibly can to get a mortgage from a lender before you actually find a house. That means getting pre-approved, not just pre-qualified. With the latter, the lender says you look good for purchasing a house up to X-amount. With the former, the lender's underwriters have gone over your application with a fine-tooth comb and committed to lending you X-amount, as long as the property appraises for what you want to borrow.

The commitment, which you should get in writing to show your seller, is conditioned, not just on an appraisal, but also on another look at your ability to repay. So once you are approved, don't do anything to upset the apple cart, like change jobs, move lots of money from one account to another, finance a new car or open a new charge account to buy a big-ticket item.

-- If you know pretty much where you want to buy, get out there and knock on doors. "That's the way my parents sold their house," says Rick Sharga of Tex-X, formerly Auction.com. And my cousin bought her first Florida house the same way.

You never know who might be interested in selling but has not yet decided to list their home. If you present yourself front and center as a ready, willing and able buyer, that may just be the deciding factor. Especially if the owner dreads the idea of having would-be buyers traipsing through his or her house during all hours of the day or night.

-- Make your offer as clean as possible. That means few, if any, contingencies. So don't make your offer dependent on selling your current house. The supply of houses for sale is so tight in many places that if your place is in decent shape, it should sell quickly anyway, so that shouldn't be a concern. If you have the financing lined up, that shouldn't be a worry, either. So cross off that rider.

For the most part, that leaves the home inspection contingency. Some buyers have agreed to forgo a home inspection altogether. That's not advisable. Without an inspection, you don't really know what you are buying. But you can find an inspector who's willing to move at a moment's notice, and offer to have the examination performed within 48 hours.

-- Don't look for the best bargains. That's where investors tend to hunt. If your competition plans to rent, they'll be willing to pay market prices. So be prepared to outbid them.

-- Many sellers are emotionally attached to their homes, so consider writing a letter to the seller outlining in comforting prose exactly how you plan to love and take care of their home as much as they do. Say how you plan to raise your family in the house, and attach pictures of your kids. If your are expecting, attach a picture of your ultrasound. Schmaltz, to be sure. But it sometimes works.

-- Check out the "first-look" websites listing foreclosed properties owned by giant mortgage investors Fannie Mae and Freddie Mac. Under government edict, these semi-public companies are required to offer their repossessed houses to first-time buyers for 20 days before anyone else can buy them.

There are some restrictions, though. With Fannie Mae's HomePath program, for example, you can't have owned your primary residence within the last three years, and you must go through an online buyer education course. Also, if you want to make a down payment of anything less than 20 percent, you must have a credit score of 660 or better.

-- Check the websites of companies like HomeVestors, the "We Buy Ugly Houses" outfit, or House Buyers of America. These companies and others buy houses on the cheap, anywhere from 50 to 60 percent of market value, from people who want to sell fast without any hassle, typically from sellers who have inherited houses they don't want.

They buy houses as-is, fix them up and resell them. "We put anywhere from $20,000 to $40,000 into them to fix them up and make them the nicest houses in the neighborhood," says David Hicks, co-president of HomeVestors.

A good number of the rehabilitated houses Hicks' 700 locally owned franchises sell go to other investors. Of course, they are resold at full value. But if you can get the ear of the franchisee in your area, maybe you can move up to first in line. Or better yet, if you can handle a "handyman special," maybe you can buy a place at a discount from an Ugly House or House Buyer franchise and save them the trouble of rehabbing the place.

There's no rule or legal requirement that homebuyers must participate in a final walk-through inspection right before closing. But those who skip it could be making a costly mistake.

Problems at walk-through don't crop up often. But sometimes the ceiling fan is missing, or the refrigerator has been swapped out, or there's a giant hole in the wall. Al Raymondi of the Ocean View Realty Group in Ormond Beach, Florida, and his clients recently discovered a roof leak during a walk-through that the sellers, who had already moved out, didn't even know about.

"Ninty-nine percent of the time, everything is perfect," said Scott Godzyk of Godzyk Real Estate Services in Manchester, New Hampshire, on the ActiveRain real estate community site. But if it isn't, you'll be glad you took the time to check.

Karen Fiddler, a broker and agency owner in Lake Arrowhead, California, tells a story on her blog about a couple purchasing a vacant house. They had visited many times prior to closing, and felt the final walk-through wasn't necessary, because "what could have changed?"

Fortunately, they heeded their agent's advice and made one last tour the day before settlement. They discovered that a heavy rain the weekend before had wiped out the backyard, washing it down the hill.

"This is an extreme example, but a true story," Fiddler posted. "Needless to say, they did not close. Had they not gone for that last look, they would have owned a home with some severe geological issues."

A final walk-through is your last chance to make sure you are getting the house you bargained for. It is usually done a day or so prior to closing, hopefully after the sellers have moved out so you can get one last bare-bones look at the place.

Your final look-see isn't a formal inspection to make sure things work as they should. The home inspector you should have hired to give the house a once-over should have done that. Rather, it is a verification tour, so to speak -- to be certain the side-yard rose bushes haven't been removed, or that the beautiful chandelier that you bargained hard for hasn't been replaced by a cheap builder-grade fixture.

The walk-through also gives you a chance to make sure there are no new damages or problems beyond what your inspector discovered. But again, Fiddler cautions, it is not to approve repairs that were supposed to be made by the seller prior to closing or make sure they were done correctly.

"The seller is responsible for handling the repairs according to the terms (of the contract), and even if everything looks proper during the walk-through, a buyer is not a home inspector," the California agent says. "If a problem occurs later as the result of the work done by the sellers, they remain responsible."

You can find any number of pre-closing checklists on the internet. Most will serve you well. But here are some things to pay particular attention to:

Be sure the a/c cools and the furnace heats. Check all the appliances, including each burner on the stove and the ice-maker in the fridge. Flush all toilets and turn on all faucets to check for water pressure. Let them run long enough to ensure that the water heater is working. Fill the tubs and sinks to make sure they drain properly, and run the whirlpool.

Collect all manuals, warranties and receipts for repairs. You might need them after you move in. Work the garage door opener and sump pump. Run the garbage disposal and trash compactor.

Look for damp, stained or wet places in the attic, basement or crawl space. Flip on all the electric switches, including kitchen and bathroom fans, and check each electrical outlet. Open every window to make certain they work easily and are not painted shut.

If, after you go through all this, you find that something doesn't meet your satisfaction, you can bring it up at settlement. If you still are not happy, you have to be willing to walk. And Lenn Harley, of Washington, D.C.'s Homefinders, has a story about that:

The air conditioning at a Fort Washington, Maryland, house wasn't working at the walk-through, even though the seller had a "certificate" from an a/c company saying that the system had been inspected. So the buyers refused to close unless the seller agreed to set aside $5,000 for another inspection and replacement.

The seller refused, and the buyers walked, according to Harley. "Contract voided, seller refunded earnest money and I sold them another house," she says. "Happy buyers."