Make various kinds of cosmetics in various shapes!
Spigot: https://www.spigotmc.org/resources/backpack-cosmetics-3d-models-cosmetic-colorable-cosmetic-backpack-cosmetic.95103/
MC-Market: https://www.mc-market.org/resources/20793/
Polymart: https://polymart.org/resource/backpackcosmetics.1211
Songoda: (pending approval)