Shred.
Shred bank and credit card statements, canceled checks,
pre approved credit card offers, bills with account
information and the like.
Guard
your mailbox. When you pay bills, don't put
them in your mailbox with the flag up. Use a locked
mailbox or the post office.
Check
your credit reports. Look for telltale markers
of identity theft, say, an address change you didn't
make or new account you didn't open. Cancel accounts
you don't use or only rarely use—open credit is
a prime target.
Scrutinize
bank statements. Monitor your accounts frequently
for suspicious activity. And don't have blank checks
mailed to your home; pick them up at your bank instead.
Be
careful at ATMs. "Shoulder surfers"
can get your account and PIN numbers.
Build
a firewall. If you use a computer at home,
protect yourself by installing firewall software.