If you've flopped or rolled, take a few extra minutes once your vehicle is righted to do some damage control. Check all your fluid levels including the brake master cylinder, radiator, power steering, and tranny and engine oil. Don't try to fire the engine, but instead bump the starter a couple times listening if oil or fuel has filled the cylinders. If you feel or hear any resistance, remove the spark plugs and spin the engine with the starter to evacuate any fluid to prevent hydrolocking the engine. Actually, it's just safe practice to pull the plugs anyway before trying to start the engine at all.