There is one and only aspect that you need to take care of to improve your credit and that is to discipline yourself. When you discipline yourself, you will pay all the installments of the loan that you have taken and your credit will improve automatically.
You can also bring discipline in other aspects of your life and you should imbued the habit of saving money so that you should require less amount of money on credit and when you have less amount to pay for credit, it will automatically become an easy task for you to pay the amount on time.
If you perform the abovementioned tasks, you are expected to improve your credit and when you improve your credit, you can avail more amounts on credit if you wish.