Put an entire outfit (including undies and hair accessories) in a ziploc bag. One bag per day. When you get to the hotel, put the bags in a drawer and they can pick one per day. Did this for Disney trip. Put dirty clothes in bag at the end of the day.
This links to a tutorial for 'seat sacks' that hold papers & books on the back of a seat - but I also LOVE the curtain rod with chalkboard pails for organizing art supplies! Love this for a kids homework table!