First, you must have a good attitude towards the world and your life, that means you must have a belief.
Secondly, you must study all the time, let the knowledge fill up your innocence.
Thirdly, don't be greedy, that could be costy.
Fourthly, be kind, do good, don't do evil.
At last, have a healthy body, spend some time on exercising. Medicines are expensive.