You can apply for a credit card issued by a major bank and not by a credit union. Banks usually report credit card activity every month to all three major credit bureaus, so you will be able to see credit score changes as fast as in three months. When you are improving your credit, it is important to make monthly payments on time with all your creditors. Try not to miss or skip monthly payments. Also, keeping balances low is good for your credit. You can use up to 30% of your available credit or pay your balances off each month.