Lightning tends to strike the tallest object in the area, then arcs off to the side. If you get caught in a lightning storm and nothing nearby is taller than you, get to a low spot, squat down (preferably on something dry), and make yourself compact; hug your knees and tuck in your head (most fatalities occur when lightning strikes the head and exits through the feet or arms). Stay clear of hills, trees, fences, barns, cars and other conductors.
If you're playing golf, stop and go home. If you're in your car, stay there; don't touch any metal parts. Lightning will arc across the metal shell, but you'll be safe inside.
Often you'll get advance warning of a strike. If your skin begins to tingle and your hair stands on end, stoop down immediately. If someone near you is struck, keep her warm and dry and try to revive her breathing as soon as possible.