The best way to remember to handle things in the short term is to put them physically in your hand or in the way. If you need to remember something on your way out of the house, put it by the front door. To remember your petrol tank cap, keep it in your hand while you fill up. Strictly speaking, this isn't remembering so much as it is physically interrupting yourself, but it works as a way to make sure you do those things you must. And if it wasn't the physical object in your way, but a note about it, you would call it a reminder, wouldn't you? This is just more direct.
Mokalus of Borg
PS - I use this all the time for outgoing mail.
PPS - And for things I can't be bothered to carry upstairs right away.