Once you find a stud to nail that mirror or wall collage into, you'll have to make sure everything is balanced and level. Instead of breaking out the chalk, measuring tape and a bubble level, use a beam of light to help you create a straight line. Don't stop there. If you plan on putting in tile, wood or vinyl flooring, drywall or cabinets of any kind, buy a laser framing square and a laser T-square. Your projects will come out right every time with less math work, fewer hassles and less waste.