I think this is wonderful, However if 2-3 slots is your maximum of what you want to do then sure why not? If you can do more and am unsure about it though, then do as much as you are able to *want* to do.
I am however going to have to disagree with zero on one thing "50% more" The thing is, once your desingning someones idea of a character, that's a straight up commission a custom adopt would be be if someone designed it then you drew it then sold it.
However, given that, you should have a cap on how many times someone can change the design in the WIP or and maybe say that have to have their refrences and description ready at hand before you decide to take their adoptable.
indeed ^^ yes but i guess zero just said 50% to give me an example of what to do( i guess XD ) however i do agree with you Exuberant having all the information ready before start the character designs helps a lot ^^
some people want to create the character themselves so they give me a description and visual references of the character they want me to create,that is a custom adoptable , however its rare for me to take custom requests atm, but, i'm thinking about opening slots for customs, like some people do with commissions here on DA, i dont know if 2 to 3 slots per month would be good enough XD and thats my question, however some people may suggest other options for customs idk XD i still dont have any idea about price for those customs either. '-'
I'd say open 2 slots a month, advertise it, and maybe charge 50% more than your standard ones, depending on complexity and how many edits are made (if it's a big blatant thing, could be miscommunication, but if the "designer" nitpicks every little thing, charge)