Have a good command over the English language. You'll find it important.
Plan what to do and keep lists of your plans,
Keep reading, including fiction,science,history,politics etc.
Keep fit. Start working out, Do activities such as yoga or jogging.
Get at least 8 hours of peaceful sleep. It keeps you fresh.
Stop staying up late. You have no idea how much damage it'll cause.
Quit smoking, drinking alcohol or any other bad habits you have.