My first piece of advice is common yet most commonly forgotten:
Drink WATER, drink lots of water and I'm not talking about juice, drink, or any old liquid.
photo from: http://en.wikipedia.org/wiki/File:Glass-of-water.jpg
I was reminded of this with a great analogy from an article: remember to site source
photo from: http://www.homewatersportstore.com/swimmingpools/
Think of your body as a swimming pool full of water. There is some maintenance required to keep this pool nice and swim-ready: first, you've got to put water into it, then you've got to treat it with some chemicals to keep it clean, and when debris like leaves fall into the pool, you'll need to fish these things out. Sometimes, you need to cover the pool, like you do with yourselves in colder seasons like winter, and because water evaporates, you will need to add water to your swimming pool with the hose to replenish the lost water. What would happen if you never replenished the evaporated water? The pool would eventually dry out, right?
photo from:http://cinemagypsy.wordpress.com/2010/01/12/seven-year-old-swimming-pool-architect/
Think about your own body again. It's hard to gauge how low or high your water level inside yourself is but one way to tell if you need water is, seeing and feeling dehydration. Are your lips chapped, your mouth dry, and do you sometimes feel dizzy or your head hurts?
photo from: http://www.lifeionizers.com/blog/news-updates/health-concerns-and-ailments/am-i-dehydrated/
DRINK WATER. Remember to keep your water level up! Several things throughout your day evaporate your water from your body, such as breathing, sweating, weather and altitude, eating salty foods, peeing, pooping, and vomiting. The Earth and your body is made up of over 70% water. It's important. Think of it this way: How much fun is it to try to swim in a swimming pool with little to no water? Not much fun at all. So, be mindful of your body needing constant water, the other stuff like soda or gatorade, may taste good, but they're still not what your body needs and they can actually help dry you out or make you thirstier. Water is a requirement for your body. Drink lots of it.
http://www.universetoday.com/65588/what-percent-of-earth-is-water/