Improving your credit score starts with finding out excactly what information the credit reference agencies have for you on file already. Get your credit report from Equifax or Experian, this is the first step in improving your score.
Lets strat with the simple things. Start paying your bills on time. Even though some creditors have grace periods, you must always pay on time. Some companies record a late payment when you are late paying by only one day.
Keeps your credit card balances low. Spread your debt over all your cards and do not allow some cards to maxed out and others with none.