The things I tend to misplace are new or temporary things that don't yet have a defined place. This can particularly be a problem if you live with someone else who might tidy up after you...
My solution is to have In Boxes in strategic spots (office, kitchen, and garage). Anything that doesn't have a place, or anything my wife knows is mine but doesn't know where it goes, goes into the In Box.
Then, once a week or when it fills up or just when I'm bored, I'll go through the boxes. It's surprising how much of the stuff in the In Box ends up going in the trash. I try hard to make sure there is nothing left when I'm done; you don't want them accumulate stuff and becoming storage destinations themselves.