After trending downward for four years, identity theft is on the rise again. Last year more than 11 million consumers were hit by the crime, according to Consumer Reports Money Adviser.

But you don’t need to sign up for expensive services offered by credit-reporting bureaus and other companies to keep your identity safe. Here’s how to protect yourself:

1. Get serious, not scared. Don’t let the horror stories freak you out. The worst-case scenario — where someone opens new credit-card accounts or commits other crimes using your name, Social Security number or other information — is relatively uncommon. The most common form of ID theft isn’t even what most people think of as ID theft. It’s old-fashioned credit-card fraud and check-kiting, with someone fraudulently accessing your credit- or debit-card account. Consumer Reports Money Adviser recommends these low-tech, common-sense precautions:

• Never give your Social Security number or other information to strangers who call, text, or send e-mail messages to you.

• Never leave your wallet or purse unattended. Don’t carry your Social Security card, rarely used credit cards, or written PINs or passwords.

• Store financial account statements, medical records, and tax filings in a secure place at home.

• Don’t post your date of birth, mother’s maiden name, first pet’s name, or other personal information on websites like Facebook, Flickr, Friendster, LinkedIn, MySpace or Twitter.

• If your bank or credit-card issuer offers free online or mobile alerts that will warn you of suspicious account activity as soon as it’s detected, sign up for them.

2. Place security freezes and fraud alerts. You can shut out ID thieves before they cause damage by placing a security freeze on your credit reports at all three major credit bureaus: Equifax (www.equifax. com); Experian (www.experian.com); and TransUnion (www.transunion.com). It will prevent anyone from looking at your credit report except for the companies that already have a financial relationship with you, certain government agencies, and other exempt entities.

3. Secure your devices. If you access the Internet on your computer, you probably already know about the need for a firewall; regularly updated anti-virus, anti-spyware, and antiphishing software; and strong passwords with upper- and lower-case letters, numerals, and symbols like #, &, and $. But you might not think about other wide-open doors to your identity. Make sure your smart phone, iPad, other mobile devices, and portable flash drives containing personal data have security applications and encryption in case they’re lost or stolen.

4. Keep an ID theft file. Because identity theft is now a fact of life, it’s a good idea to set up a folder for certain documents and data and keep it in a secure place. Consumer Reports Money Adviser suggests including credit reports, security-freeze documents and passwords, copies of annual privacy notices, security-breach notices, and potential ID-theft evidence, such as mail to your address in someone else’s name.

5. Review all your personal data files. Check your credit report periodically for items that you don’t recognize — such as accounts, judgments, liens, collections, bankruptcies and other possible footprints of identity theft — and dispute all erroneous and fraudulent information.

6. Stop unsolicited credit-card offers. One way crooks steal your name is by swiping preapproved credit offers from your mailbox to open an account. You can stop credit bureaus from selling your name to lenders by going to www.optoutprescreen.com or calling 888-567-8688.

7. Monitor accounts often. It’s no longer enough to wait for your monthly credit-card or checking account statement to look for suspicious activity. For added protection, sign up for online access to your accounts and check them regularly, even daily.

8. Respond rapidly. If you suspect you’ve been a victim of identity theft, act quickly. Immediately contact your creditors and financial institutions to report unauthorized charges or debits, and close any compromised accounts.