Take control of what you ingest in your mind.
Be careful about who you hangout with because even your friends can poison you without knowing it.
Negative thinking can bring you down. This kind of thinking leads you down to a dead end path that goes no where or goes somewhere that no one wants to go. Where your thoughts are control your focus. If you are thinking negatively then you are going to see the negative in every situation.
Even in the worst possible situations you can think about what good will come out of it.
Do not make things harder on yourself than they have to be. See the world as conspiring in your favor.