Two credits cards with very low balance. So pay em off if you got them and get rid of the high interest ones if got more than two. Dispute all past BS on your account and sometimes they'll remove stuff. Just make up some shit about you paid that off or settle the debt. Most of the times if its over 3-5 years they just drop it if its not major. Buy a house! It'll jump that sucker up big time....but have to have decent credit in the first place to het a good interest rate. Long good accounts are great. Don't have too many credit checks and if have a bunch you can contact the credit bureaus and tell them it wasn't authorized, you were just browsing or something.
I've done half of these and it worked. Disputed a bunch of old stuff and hard inquiries, payed off my credit card, and opened a new line of credit and kept it low(0), then bought a house.
Mine jumped up quick over about 6 months. The credit cards will show the quickest. Then any disputes that go through as they usually take a few months, then from there its whatever.
Most banks, and the online credit agencies have advice to help. I'd check with them on your specific credit problems.