I do not have a hard list of things I refuse to draw. If you are unsure, please ask.
I require a certain degree of artistic freedom to proceed. If you are getting a commission from me, be prepared to provide a visual reference of all characters, places, or objects involved (if you do not have a visual reference, I will help you to create a very basic one at no charge). If the personalities of the characters are important, be prepared to describe them to me ahead of time. You should tell me what characters you want in the picture, in what general configuration or performing what action(s); beyond that, it is my job to determine how best to frame and execute the commission to accomplish the requirements you set before me in the subject matter. I do not generally provide WIPs, but if you have a good reason to need one, I will oblige.
Once the commission has started, I am bound to create for you a work of art that encompasses your given subject matter above. I will make every effort to be true to the subject matter given, within the expression of my artistic ability. With the exception of mistakes (for example, if the fur color is wrong, number of tails is wrong, or I used the wrong reference), I will not make changes to the work given to you upon completion. It is your responsibility to effectively communicate your desires before I begin.
If I feel that your requirements leave no room for artistic expression, I will likely suggest that you seek another artist. Otherwise, I will work diligently to fulfill your requirements within the nature of my own oeuvre.
Withdrawing Payments
I will not dispute payment withdrawal if I have not started on the commission. If I have begun work on it, I will dispute the withdrawal on the basis of unpaid labor. If I feel I have delivered a finished piece that meets the requirements given within a reasonable margin of high quality, I will dispute any failure to pay.