Simply put, you can't put things away if there's no place to put them. If items are piles all over the place, it is likely that you never designated a particular spot for them. In other words, the item has no "home."
Solution: Take the time to assign each item a single, consistent home, e.g. hats always go in this basket; scissors always go in this drawer. Label everything so you'll always remember where it belongs and easily find it when you need it.