Sage advice from an old carpenter I once worked with:

Measure twice; cut once.

If at first you don't succeed get a bigger hammer; but don't force it.

A two-by-four (2X4) isn't.

Rub a finish nail on the side of your nose and it will be less likely to split the wood when you drive it in.

Never suck on an iron nail. (The same goes for "coated" nails.)

If you're hungry enough, Saltine crackers and Vienna sausages (always referred to as, VY-ennies)and a "Cocola" (aka Coca Cola) can make for a good meal.