Reduce weight to reduce pressure on your stomach. Wear loose clothing. Do all the yoga excercises for digestion. Most of these stretch the torso in one way or another and really help work the poop through which lets the stomach empty faster which keeps the acid off the valve.
Stay upright: Elevate your upper body (from the waist up at least) when you sleep. Walk, stand or at least sit up after each meal.
Sleep at an angle. Doctors will tell you to put a 6" set of block under the bed frame at the head of the bed. Another possibility is to use a "Bed Wedge" which raises only the top half of one side of the bed and so keeps you from sliding off all the time. Must lift from the stomach up or will not be effective. I just use two pillows: One laid flat under my ribs from just above the hip to under my chest and another, folded in half (or two more stacked) under my neck and head.
Avoid:
Eat: