John T. Reed is a real estate investor and prolific author. He's also a pain in the backside for the modern-day snake-oil hucksters who peddle get-rich-quick real estate schemes on late-night TV and radio.

Their spiel goes something like this: Attend their seminars, take their classes and buy their books and DVDs, and you'll make millions buying houses on the cheap and reselling them in short order.

Reed says he's often asked what he thinks of a particular instructor or his programs. He isn't familiar with the work of every one of these charlatans, but he has built a list of observations that potential customers can use to separate the bad guys from the good guys. Here's a short synopsis of some of the points on his "B.S. checklist."

-- Emphasis of luxury lifestyle. The best teachers rarely mention how well they've done and don't need to wear their supposed affluence on their sleeves. Those who throw the bull have their photos taken with Hawaiian backdrops, stretch limos and Lear jets to help create an aura of financial success.

-- Best of the best. The bad guys' bios are full of baseless, subjective phrases like "the leading" this or "the No. 1" that. Watch out for words like "innovative," "famous" or "spectacularly wealthy."

-- No regrets. Every real estate investor has made at least one bad deal in their lifetime, but not the hucksters. They rarely point out the pitfalls of the business. Everything has a downside, but not to these guys.

-- No bad news. Similarly, according to the snake-oil salesmen, no new court decision, law or economic trend ever holds bad news for the real estate sector. These rotten apples always see opportunity, even during times when smart investors should retreat to the sidelines.

-- Universal techniques. Another way that suspect counselors boost sales is by trotting out "new," and often obscure, methods. But rather than explaining when one tool or another is appropriate, they leave the impression that all techniques are suitable for every deal. In reality, there is no one-size-fits-all real estate strategy.

-- Motivation. These false prophets wrap too much of their appeal in motivation. There's nothing wrong with trying to rally the troops, but too many "you, too, can do it!" platitudes border on the dishonest.

-- False claims. Virtually all the fake gurus claim to practice what they preach. Baloney. They spend far more time on their seminar business than on their investments, if they have any at all. They may have done some deals -- maybe even many deals -- but that's ancient history. Now they are selling, selling, selling.

-- False offers. The bad guys sometimes offer to join their students in investment deals, but they never do. They may invest in one or two deals someone else brings to the table to be able to say they do, but for the most part, money never comes out of their pockets -- it only goes in.

-- Without money. To overcome the objection of students who really have no money to invest, the dishonest professors stress no-money-down techniques, which are fundamentally unsound. These schemes are "a way to part fools from their money, not a way to invest in real estate," Reed says.

-- Red flags. Treat these words as flashing "steer clear" signs: surefire, cinch, always, easy money, risk-free, safe, magic, bulletproof and automatic. No such thing, at least not in real estate.

-- Fake testimonials. When real people testify to their success using the guru's techniques, they use their full names and locations. When paid actors do so, they only use their initials or their first name, so you can't check them out and confirm their validations.

-- No recording. The instructors who bar you from recording a free promotional seminar do so to prevent you from having evidence of the fraud they are perpetrating.

-- Hard sell. If there's a push to buy increasingly expensive classes, books and DVDs, you are in the hands of someone who thinks they have a sucker on the line.

-- Show me the love. They'll tell you they're not in it for the money. Rather, they are telling the world how to make money in real estate out of the goodness of their hearts. Yeah, right. If so, why not just give away their knowledge, instead of charging thousands for it?

Donald's Trump "university" isn't the only school of higher learning in hot water these days. It's joined by the "fix and flip" seminars sold by Armando Montelongo, the onetime star of the A&E series "Flip This House."

In a federal civil suit filed in San Francisco this spring, some 160 students claim they paid thousands to attend Montelongo's classes that would supposedly teach them how to buy run-down houses, fix them up and sell them for a quick profit. But, the suit alleges, the courses served only to enrich Montelongo.

According to Montelongo's hometown newspaper, the San Antonio Express-News, "students typically paid $1,500 for an introductory course, where they were recruited for 'bus tour packages' that cost up to $54,000. ... Classes on 'asset protection' cost $27,000 more. 'Market domination,' cash flow programs and master mentor classes cost up to an additional $55,000."

The suit maintains that Montelongo and his companies have "destroyed livelihoods, wrecked marriages, driven students into clinical depression and even resulted in suicide."

In an email to the Express-News, Montelongo's attorneys essentially dismissed the suit, saying it was filed by a bunch of lazy students who couldn't follow the pitchman's instructions.

Of the "more than 1.5 million people" -- hold that thought -- who have taken the classes, the email said, the "small group" of plaintiffs "have decided continuous hard work is not for them. Now, they have chosen to try and make money the easy way by clogging up our legal system with a frivolous lawsuit."

The suit accuses Montelongo and his companies of violating the Racketeering Influenced and Corrupt Organizations (RICO) Act by committing wire fraud and conspiring to deceive investors over a number of years. It estimates actual damages at $4 million, but triple damages can be sought under the RICO law.

Back to that "1.5 million people" figure: yikes. That's a lot of customers. No wonder Forbes once estimated Montelongo's net worth at $200 million.

Had the disgruntled students -- and possibly many others who have not come forward, perhaps too embarrassed to admit they might have been fleeced -- done a little sleuthing, they might have saved themselves a lot of time and money. An online guide called "The Top 20 Real Estate Gurus: The Good, Bad and Ugly" gives him just one out of five stars, and the Amazon reviews of his paperback, "Flip and Grow Rich," are less than scintillating. "The 'secret' revealed in this book is that you need to sign up for Armando's seminar," said one reviewer. "Don't waste your money."

An 2013 article in Forbes describes him as a "house-flipping huckster" who offers "long weekends of questionable advice, raucous showmanship and tours of foreclosed homes in some of America's poorest sections." Writer Abram Brown asked him to produce alums of his seminars who made millions by using his methods, but he either wouldn't or couldn't.

Whether the suit against Montelongo will prove successful is hard to say. But he's probably right about one thing: Millions of people have attended his and other so-called gurus' seminars.

As an owner of rental houses, I see the handiwork of these "instructors" almost weekly.

In just the last few days, I have received four letters and postcards asking me if I want to sell a property. Some are typed, some are made to look handwritten (while still being mass-printed), but they all say essentially the same thing. They promise a quick, clean, "as-is" cash sale -- no sales commission or extra fees. They'll even pay all closing costs. What they don't say is that they only want to give me half what the place is worth on the open market.

What this tactic says to me is that either a lot of people have taken the same class, or a lot of these get-rich-quick guys are teaching the same thing.

The advice here is to stay clear of anyone who promises you'll earn a fortune by following their investing techniques. If it's so easy, why are they peddling seminars, books and videos instead of flipping houses full-time themselves?

It may look simple on "unreality" TV, but it isn't.

(Next week: How to spot a scam artist.)

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.