Payment History (High Impact on Credit Score)
Keeping on top of your payments should improve your credit score. Although you should try to pay your full balance each month, making the minimum payment should be enough to protect your credit score from harm.
Credit Utilisation (Medium Impact on Credit Score)
Using more than 25% of your available credit on one or more of your credit accounts can lower your credit score. For example, if you have a credit card with a limit of £1,000, you should try to spend less than £250. Otherwise, your credit score could drop. And if you go over 50%, it could drop even further.
We know it's silly. Unfortunately, that's how the industry works. We think it's something you should know about, though.
Account Activity (Low Impact on Credit Score)
Managing different types of credit can help improve your credit score. For example, if you can use a credit card, an overdraft, and a phone contract responsibly, you'll seem like you have a good handle on it. If your only type of credit comes from a lot of credit cards, it will seem as though you don't have much experience.
Keep in mind, this is just a guide, and it's generally best to borrow responsibly and only what you can afford.