2. Take care of joints and teeth. Once they degenerate it's impossible to reverse the process.
3. Get financials straight. Know tricks to increase your credit score and keep it as high as you can. Also knows to invest a bit and make sure not to borrow money to invest because you are probably not that good.
4. Find something you can spend a life on. Something fundamental such as astronomy, mathematics, physics, geology, etc. The point is not to excel at these things, but to find consolence when you feel being ditched by the whole world. Reason I recommend those topics because not only you understand the world better after studying them but your mind will be sharper.
5. Stay away from gambling unless you are very disciplined. And if you do, don't play against the house and don't borrow money to gamble.
6. Stay away from drugs. Maybe stay away from smoking too. You don't need those for "artistic inspiration" or other enhancements. Exercising and reading get you much further. Enhancements through medication also bring side effects in the long run.
7. Build your personal brand. Be sound and reasonable. Knows how to communicate effectively. Learn to speak in public. Soft skills are tough to pick up and grow.