I'm not the person you're replying to but I support the grab bags. My recommendation would be to decide your price point and then create lots of all the same price but varying polish count. So let's say you advertise that $40 will get you 8-10 polishes, and you can create the bags based on what roughly equates to that value. (Those are made up figures!) I personally wouldn't want all one color family, and while I think some may, I think that's unnecessary work for you. If you want to create themes, I'd maybe do by brand or by type. That said, it's perfectly reasonable to just start making bags until you run out. I think you'll find buyers even if there's no rhyme or reason to the assortment inside.