I came across a pretty easy way to raise your credit by lowering your overall debt utilization. From DebtKid.com:

Call your current credit card companies. Ask them if they will increase your limit. Even if you owe $1000 on a $1000 limit card, if you’ve been paying on time, there is a good chance they will raise your limit. This provides more “available credit” (debt to limit), a big key to raising your FICO score.

How it works

Let’s do a quick example to show how effective this is:

Let’s say you have three $1000 limit credit cards, each each has a $900 balance.

Card #2: $900/1000 limit. 90% utilization.

Card #2: $900/1000 limit. 90% utilization.

Card #2: $900/1000 limit. 90% utilization.

You give a quick call to each card. Card #1 raises your credit line to $1500, Card #2 to $2000, and Card #3 to $3000. Great!
Now:

Credit Card #1: $900/1500 limit. 60% utilization.

Credit Card #2: $900/2000 limit. 45% utilization.

Credit Card #3: $900/3000 limit. 30% utilization.

Total debt: $2700. Total Limit: $6500. Overall: 42% utilization!

Like DebtKid advises, it’s best if you don’t use this extra credit, or else it defeats the purpose of lowering your debt to limit ratio. It’s also important to remember to check if a credit increase can be done without a hard credit pull, which could have an adverse effect on your credit score. In addition, this method is most effective when you have a lot of debt on many cards that are close to the limit. But with our nation’s consumer debt increasing daily, I suspect this many apply to a larger portion of our population than it should.