Pay On Time
Payment history is the largest weighted category for FICO credit scores, consisting of 35% per Fair Isaac. If you have not been paying your bills on time, now is the time to start when you are working on repairing your credit. Just by making on-time payments every time, your credit scores may improve quite quickly. You need to make this a main priority due to the impact timely payments has on your credit report.
It is important to note that FICO requires every consumer to have a minimum of one account open for at least six months to pull a credit score. Within the most recent six months of the account being open, there needs to be some activity for the FICO software to grade. This does not need to be an open credit card, but could be any account in which you make payments.
Credit Repair and Accounts
Tying in with account history, if you do not have any open accounts then credit repair cannot do its job of improving account information. Make sure you have plenty of accounts open so FICO has information to pull and score. If information is too limited then the FICO model will not have the facts they need to deem you a low-risk consumer and you will probably receive low FICO scores.