Do not drink any caffeine whatsover. Just because the rest of America is doing it, doesn't mean it's a good idea. I see every body chugging energy drinks and 5 hour energy, do not do that! I know it may seem hard at first, but it can be done. I work graveyard, and I do not drink any caffeine aside from 1 green tea a day for health reasons, not for the caffeine. It can be done if you have a set routine, and get at least 7 hours of sleep. If I can work graveyard with no caffeine, that proves that humans do not need caffeine to survive. Think about thousands of years ago, humans didn't have caffeine, yet they still got up in the morning to farm or to hunt. They didn't roll over and hit the snooze button. Caffeine is not necessary.
Lay off all this starbucks crap everybody else is drinking. No soda, no tea (aside from green tea if you are into that), and no coffee. Avoid other things that may have caffeine in them like too much chocolate.