Timely Repayment of Bills
The maximum weight in your Credit Rating is given to the timely payment of bills. If in past for some reasons your repayment has been delayed try to be regular now. Even when the amount due on you is less, pay it before the due date. It will help you reestablish your credibility and improve your score.
Manage New Credit Wisely
Several credit inquiries during a short period means you are attempting to open multiple new accounts, and that lowers your Credit Scores. Credit scoring software usually recognizes when you are shopping for a single loan within a short period of time, such as a home loan. If multiple inquiries are necessary, have them pulled as closely together as possible. Checking your own credit report does not affect your scores.

The Types of Credit You Use
A mixture of credit cards and installment loans, loans with fixed payments, can help raise your score if you manage the credit cards responsibly. Having many installment loans can lower your scores since payments remain the same until balances are paid in full. Closing an account doesn't remove it from your report. It may still be considered for scoring purposes.
Keep Your Credit Card Balance Low
It does not matter what your credit limit is, what matters is how well you pay your balance. Maxing out your credit card bills can lower down your score by 70. Hence keep you balance as low as you can.
Don't Open New Credit Card Account
Opening up a new credit card account will lower down your credit score by an average of 10. It is better to settle down with your previous credit card.
Pay off Debt, Don't move it Around
Owing the same amounts, but having fewer open accounts, can lower your score if you max out the accounts involved.
Don't close unused accounts, because zero balance might help your score.