hanging a picture frame, put a dab of toothpaste on the frame where you need
the nails to be. Then simply press against the wall to leave marks (which
can later be wiped) as guides for hammering in.
Another way to clean a chopping board is to cover liberally with Kosher salt
and leave overnight. Scrape off with a cloth in the morning to find the salt
has absorbed all moisture to leave your board clean and dry.