In the top drawer, we keep our fitted diapers (the mainstay of our stash) and the accompanying covers. The next drawer houses our going out and nighttime diapers, which for us are AIOs and pockets, as well as the doublers for them. And in the bottom drawer, we keep our small selection of prefolds, which we mainly use as burp cloths at this point or emergency diapers when I've put off laundry a bit too long. On top of the cart, we keep a basket that has our cloth wipes, a baby first aid kit, and a change of clothes.
Even my scatter-brained husband has been able to keep the diapers grouped appropriately, and so far the system is working great for us!