Colourable Zentangles and mandalas

Hi everybody! I'm tinking in a new project! Make colourable zentangles and mandalas to sell and print \o/ but I've never made internet transactions before (and never make this in the real life too, I'm a looser T.T) so I'm having some difficulties. I tried to sell one of my figures as a print on DA but I'm a totally noob :/ so the prints get to much big and expensive. Anyway, it's a project that needs more planing.