credit score plus

How to I bring my 506 credit score up?
I have 3 credit cards and 2 checking accounts closed about 2 years ago when I was 18. I have a steady job now and already paid off 2 of the credit cards plus what I owed the 2 banks. What else can I do to bring up my credit score?
pay your bills on time live within your means
GOOD LUCK!

