So a few years ago I got myself in a bad car loan and the car was eventually repossessed. Since my good friend, Raul, owns a car dealership (Napleton Hyundai) I asked him what the best way to raise my credit score was.
He said get a few secured credit cards and pay them off each month. A secured credit card is one in which you put down a deposit (I did $300).
So I went to PNC bank and got my secured card. I paid off the card each month (on time). After 3 months I noticed my score went up about 40 points. After six months it went up over 80 pts.