How To Improve Your Credit Score

Check Credit Report.
Order your free credit report from annualcreditreport.com each year and check for errors. If you find any, file a dispute with the credit reporting agency to have it fixed.
Pay your credit care bills on time.
Prove to the lenders that you can reliably pay your debt on time every month. Download a bill paying reminder app on your phone to help you pay bills on time.
Keep your monthly bills low.
Ideally, you'll want to pay your monthly balances entirely, but if that's not possible, keep the total credit used under 30% of the available credit.
Clear up any collection accounts.
Pay off your debt as soon as possible. These accounts stay on your report for 7 years, so the sooner you pay it off, the quicker it will come off your report.
Don't open a lot of new accounts at once.
Each time you open an account, the creditor makes a "hard inqury" on your credit. Each inquiry lowers your credit score by a few points.