1. Try to Get Positive Accounts Reported: You know that the credit bureaus typically don't share information, but it can be frustrating if one of your good, paid-on-time accounts doesn't show up on all of your credit reports. What's worse is when a credit account isn't reported at all. Some creditors simply don't bother to use credit bureau services, and others deliberately hide the histories of their best customers for fear that their competitors will swoop in.

Although you can't force a creditor to report an account to a bureau or report more frequently, you can always ask. Sometimes it's all but impossible to get your on-time payments recorded. Most landlords, utility companies, and phone companies will only report you to the credit bureaus if you screw up. (So be sure you don't screw up.)

2. Borrow Someone Else's History: Being added to someone else's credit card account as an authorized user can instantly improve your credit report if that person's credit is in good shape. (The opposite can also happen, so make sure you pick the right person.) A cooperative credit issuer imports the card user's account history into your report so that you can benefit from the other person's good financial habits. Not all credit issuers do this import, though, so it's important to call first and ask. There's another plus to being an authorized, rather than a joint, user: You're not liable for any debt the original account holder runs up.

3. Get Some Credit or Charge Cards If You Don't Have Any: You need to actively use some plastic to rebuild your score. Although it's anyone's guess how many cards are optimal, it's a safe bet that you'll eventually need more than one - but less than a dozen. If you still have accounts you can use, that's great. If your accounts have been closed, you'll need to start from scratch.

4. Apply for a Secured Card: Secured cards give you a credit limit that's generally equal to the deposit that you make. You want a card that reports to all three credit bureaus, that doesn't charge an application fee or outrageous annual fees, and that converts to a regular, unsecured card after 12 months or so of on-time payments.

Get department store and gas cards. These cards tend to be the easiest unsecured plastic you can obtain. After you've had your secured card for a few months, apply for one of these - and perhaps a second one about six months later. Don't rush this process, because applying for too much credit in too short a time period can hurt your score.