Your credit score reflects how likely you are to repay debts on time. A better score means access to lower rates and larger amounts.
5 things that help
1) Pay instalments on time. 2) Keep your debt-to-income under 40%. 3) Avoid too many applications in a short time. 4) Don't use your full card limit. 5) Check your Credit Bureau report regularly.
Estimate your score for free in Calculators → Credit score.