I just read a great thread on another forum called Lifebacks: post you tips for everyday living. My favourite tip was measure your hand from the tip of your longest finger to the base of your palm and remember that length. Also measure one joint of the same finger. You can now use your hand or finger to efficiently measure the length of many everyday objects.
One from me is if you drop something fragile use your foot to break the fall. It works for me about 90% of the time.
I know you guys are full of tips for the workshop but how about daily life?