Nobody wants to walk up and down a flight of stairs each time something needs to be put away. Craft blog Sew Many Ways suggests giving every member of your family a "crap basket" to put their stuff in.
The idea is so simple it seems obvious once you think about it. Each person is responsible for their own basket, and they just carry it upstairs whenever they are ready. It also helps teach everyone to get in the habit of keeping things clutter-free by taking something with them when they leave a room.
Tool Time Tuesday...PVC Dog Gate and Stair Baskets Too [Sew Many Ways via BuzzFeed]