It's obvious you need to reduce any debt. In doing so, you'll keep your debt to credit-limit ratio. Get this as low as you can.
For instance, if you've got $5,000 of debt with a $6,500 credit limit, your ratio is 77% ($5000 divided by $6500). This means you've used up 77% of your available credit. This will hurt your credit score.
Closing unused accounts is a common myth when it comes to improving your credit score. In fact, closing accounts can actually hurt your score. Why? Because a part of your score is calculated by determining how much debt you have versus how much available credit you have.
If you close out your available credit, your debt becomes a larger percentage of the credit available to you and may lower your score.
You can improve your score by spreading your debt among credit cards even if your debt remains exactly the same. This is because a credit card that's almost maxed out is more likely to be detrimental to your score. Consider transferring that balance to one or more other credit card accounts.
Your score can be affected if you fill out too many credit applications over a short period of time. While you can acquire multiple cards over time, it's just not a good idea to sign up for too many of them at once. This makes you look desperate for any kind of credit.