Then stretch each major muscle group with a little extra time on the muscles you plan to train that day. Eat enough, but not too much. Avoid eating protein until after your session. Drink plenty of water. Drink water frequently during your workout to prevent overheating.
Plain water is better than juice or a sports drink.
To promote balance and avoid injury, work each set of opposing muscles equally. Don't over train. Doing too many repetitions of one exercise can eat away at your muscle mass, making you weaker instead of stronger. Gradually increase the length and intensity of your workout. Give yourself time to recover.