I've never even crafted a shield; I've got a few tokens on my old/"real" world, safely stored in a chest. I *think* there may be one displayed in an item frame, but it's been a couple of years since i've played in that world... If I ever go to the End, I suppose I'll take one with.
Most of the time, I keep a stack of torches in my off-hand. Occaisionally if I'm out hunting at night I'll keep my sword in my main hand and my bow in my off-hand; and of course if I'm fishing/breeding animals/trading with villagers for mending exp my off-hand gets whatever tool I'm repairing.