Thanks to all for the comments on my milk crates. All you need to do is buy a 1"x12"x10' pine board, one 1"x4"x10' pine board, 4 8"x8"x16" blocks. Space the blocks out evenly, nail the 1x4 to the 1x12, sit that on the blocks slide your milk crates in, they fit snugly between the wall and the 1x4. They are not tippy at all, when you want to clean, simply pick them up dump in the trash and replace with new straw.