Use zippered pencil pouches to organize puzzles instead of storing the bulky boxes. Cut off the image from the front of the box and store it in the bag, too. (This blog post has several great ideas for organizing kids toys.)
Life size Lincoln Logs made out of pool noodles~ 15 pool noodles from the dollar store cut in half cut notches out easily with scissors = there are no words for how amazing this looks! EVEN I COULD HAVE FUN WITH THIS, AND I'M A GROWN ADULT.