Several years ago my family was constantly late going places because of "Oh no, I forgot to unplug..." The usual culprit was the electric curlers. I finally came up with something that stopped the problem.
I inserted an old-work box in the wall above the bathroom outlet, redirected a couple of wires, and installed a mechanical timer switch. If we get down the road and remember the curlers are still plugged in it doesn't matter. They CAN'T be on longer than 30 minutes.
I know that many devices now have automatic shut-off timers so this may be unnecessary for many people. I would also point out that if a GFI outlet is involved take special care that you don't negate the protection it provides. It would be much easier to add this feature in new construction, so plan ahead.
Maybe this idea will help someone some time.