1) Pay the amount due on everyone of your account in full and on time every time.
2) Limit your utilisation of credit – Do not use all your available credit to the the maximum allowed, manage your debts responsibly and avoid applying for too much credit within a short period of time .
3) Maintain a healthy mix of credit – (Store accounts , credit card , home loan, service contracts such as cellphone accounts and so on in order to establish a strong credit history check your credit report and your credit score regularly.
Source : TransUnion