This shouldn't be news to you, but Drink your Water! I don't mean have one or two glasses, I mean drink nothing but water ALL day. No more soda or juice, there really isn't much good for you there. I suggest buying some sort of re-usable water bottle, I like the SIGG bottles. Just keep it filled and on you ALL day long.
First of all drinking water all day will help you from over eating. Also keeping your body hydrated is VERY important. If you are thirsty you waited too long to drink something.
Water is crucial for life for a variety of reasons...
1. In blood it helps transport glucose, oxygen, and fats to working muscles
2. It eliminates waste products
3. It absorbs heat from working muscles
4. It regulates body temp
5. It lubricates joints and cushions organs and tissues
If you absolutely NEED some sort of flavor to your water then go buy some crystal light packets to add to your bottle. They have tons of different flavors and they are only 10 calories a packet. It's always better to have straight water, but these aren't bad if it helps you to get your water intake up.