NEW YORK (CNNMoney.com) -- To protect themselves from litigation, regulators and the risk of high turnover, companies are stepping up their screening of job candidates - and, in some cases, current employees.

A recent survey by staffing firm Spherion found that 79 percent of companies said they conduct background checks on some or all job candidates, 50 percent perform drug tests and 33 percent said they perform credit checks.

More than half of companies that use these screening methods also said they have increased their use of them since 2001.

Besides verifying the details on your resume, employers most commonly screen for criminal behavior, drug abuse, regulatory violations and -- of late -- inclusion on terrorist watch lists.

But they also may take an interest in tax liens, bankruptcy filings, a habit of bouncing checks, ongoing divorce and custody proceedings, driving violations and medical conditions.

That's because employers are concerned that someone with serious monetary problems, health issues or family concerns might not be fully focused, said Tal Moise, CEO of background screening firm Verified Person, and Cynthia Shapiro, a former human resource executive and author of "Corporate Confidential."

Gauging a job candidate's temper, social skills and reaction to stress also is a growing part of the screening process.

You may be asked the extent to which you agree or disagree with a series of attitude statements, quizzed on how you've handled tough situations in the past or asked to role play -- e.g. playing a salesman faced with five or six calls from irate customers, said Carl Greenberg, Spherion's vice president of selection and retention.

Another technique is to catch you when your guard is down, according to Shapiro, who now advises people how to get through the interview process.

For instance, a company might call you knowing it's a bad time - think dinner time with crying kids in high chairs.You'll raise a red flag if you confess your house is chaotic and you're stuck with double-duty because your spouse is always working. Why? Home life is a top distraction at work.

Another technique, Shapiro said, might be to ignore you for several days during the interviewing process -- they want to see if you'll send a scathing e-mail, she said.

Think only a handful of HR folks use techniques like these? "Everyone has," Shapiro said. Everyone, that is, who has gone through serious hiring-training, where such tricks are taught.

Once you get a job, the digging into your background may not end. According to Moise, as many as half of his clients employ ongoing screening of current employees.

It is most common at two types of businesses: financial services firms and healthcare providers.

Financial services firms can be held liable if an employee has been convicted of a felony before or during their employment at the firm.

Healthcare providers can be financially penalized if any employee working directly with Medicare or Medicaid patients has been convicted of battery or a drug-related felony, has had his professional license revoked, been subject to other disciplinary action, or submitted fraudulent charges to an insurer.

But other businesses may remain on alert. Large organizations that work with children, for instance, might monitor employees for sex-offender convictions. Or delivery companies might monitor employees for driving violations and sex-offender convictions.

You're never privy to the real criteria a company uses to assess you. But you can do some basic things to buffer yourself for a screening.

Your goal, Shapiro said, is to "be a really good bet. They'll go with the safest choice."

Review your records. Just as you might try to boost your credit score before applying for a mortgage, you might do the same before applying for a job. (Start by avoiding these surefire ways to lower your score.)

Also check that there's nothing erroneous about you in various public records. Mistaken identity is not unusual in records organized by name, since a lot of people may share the same name.

You can order your own background check from public-records aggregator MyPublicInfo.com or information brokers like ChoicePoint.

If there is an error -- e.g. a DUI charge in a state where you've never been -- take steps to clear it from your record. But if you can't do so in time, alert a potential employer about the situation before a background check so he's not alarmed to see it.

Don't get too personal in interviews. Never talk about things that a company is legally prohibited from asking you about directly, such as medical history, family circumstance or bankruptcy issues, Shapiro said.

If an interviewer makes a casual comment about his problem back, don't share information about your bout with cancer.

Or, if you see a picture of a lovely child on the interviewer's desk, don't mention how you never like to miss your daughter's Thursday afternoon soccer game or how stressful your ongoing custody battle is.

Stay positive. Never trash talk a former employer, Shapiro said. When asked to talk about the worst boss you've ever had, for instance, share a story about a challenging situation that had a silver lining.

Don't let loose on the Internet. Although it is still rare, Moise said, companies may check your online profile. So expressing a love of anarchy on your blog might get you knocked out of contention.

Think small. Despite always getting far in the interview process, a client of Shapiro's couldn't land a job at big companies because he had filed for bankruptcy after a divorce. But he did get hired by a small company.

If your background check reveals a potential red flag -- e.g., you sued a former employer or declared bankruptcy -- you might apply to small companies since they are less likely to conduct a rigorous background check.

Once hired, do a great job if you eventually want to re-enter the larger corporate world. The key, Shapiro said, is "to put time and success between you and those events."