Since nobody has made any suggestions yet, I'll start the ball rolling. Ensure that your breaker (or fuse) box and house wiring are normal and proper. If it's an old house, you might want to have a licensed electrician inspect it. New houses are required to meet pretty rigid standards when built.
If all's well, go from there. Things you can do: Don't overload outlets with too many devices. Don't use old, cracked, or damaged extension cords. If you experience a shock or tingle when using or touching any electrical device, disconnect that device and get it repaired or replaced.
More ideas, comments from others?