One of the most important thing is. At the statement date, your balance should never exceed 30-35% of your CL. Even if you make all your payments on time, your credit score will not go up if you continue to come close to maxing your CC. CL usage and on time payments are two of the biggest factors combined with hard inquiries. Don't apply for many CCs in a short period of time. A hard inquiry stays on your report for up to 2 years.