Sleep, lay down, with your upper half body in an inclined position. This prevents your stomach contents from putting pressure against your esophagus. Let gravity help you to keep food where they belong, in the stomach digesting.
Eat small meals instead of large meals. It is preferred to eat 6 small meals a day, instead of 3 large ones. The stomach has a feedback mechanism, if it's overloaded with food, it increases digestive acid production, which in turn increases the chances of refluxed food.
Avoid exercising before and after you eat. Exercise! Just dont do it before or right after meals.
Avoid putting pressure on the stomach after meals. Putting pressure in the stomach can sometime push the acid upwards into you esophagus.
If overweight, try to lose some weight. Again, being overweight just adds pressure to your organs, such as your stomach.
Drink water. Not too much at one time, because it will dillute the digestive acids in your stomach triggering a feedback mechanism which makes the stomach produce more acid.
RELAX!!! Too much stress is bad for overall health.