If you use your credit card and then pay off the credit card balance in full each month you should see a significant improvement in your credit score.
Paying off your credit card balance in full each month is a great way to build your credit score up fast and by paying off the credit card balance in full each month you can raise your credit score by 100 points in just 1 to 2 months.
So if you can do so always pay off the credit card balance in full after using your credit card since having your credit card balance and credit utilization go down your credit score goes up as a result.
When I paid off a maxed out card in full my credit score raised by 100 points in just 2 months.