A tip that's helped me: when you finally find the thing you misplaced, and are done with it, don't put it back where you found it, put it in the place where you first looked.
This reminds me of a rule I have for naming things in code (functions, variables, etc).
Say you add a function, and then the first time you call that function, you call it by a different name. Don't fix the function call to match the original name, but instead go back and change the name to match how you tried to call it. The state of mind you are in when you called the function is a better guide to naming than the state of mind you were in when you implemented it.
