Designate a place in every room as, “the place I put things.” Use positive reinforcement to train yourself to put things down in that space. Every time you use a drop zone, give yourself an attaboy/girl. It needs to be big enough that it can hold a few things, keys wallet, cell phone, but not so large that things can get lost in it. You don’t want too many drop zones, but you need to have one always handy. Keep them uncluttered when possible so that they’re always available. Dissuade the people in your life from “cleaning up” these spaces. Now, when you lose something, you’ve got a good chance of finding it by checking all your drop zones.