Well, neither and both. Professionally speaking, I am neither a pro-sub or pro-domme. I have never received training for either and I learned my understanding of both from the internet and books (and through a modest amount of experience) like most amateurs. Most of my sessions with new clients do not have a pre-negotiated dynamic and that is my preference. Afterall, we are strangers upon meeting and it is hard to know what dynamic will naturally flow from the interaction of our personalities. Do not assume that our session will have a particular dynamic just because you've requested services that are stereotypically associated with one side or the other. With that said, I would consider myself a switch and do enjoy playing both roles.
As a Domme, I prefer play of a cerebral and/or sensual nature. That includes tease and denial, edging, body worship and some humiliation such as objectification, small penis humilation and sissification. (Please note, I will not agree to a humilation session on the higher end of the intensity scale for a first meet). I do not enjoy impact play and do not feel qualified to offer medical play (including sounding).
As a sub, I am a bratty sub. This sub style is not well matched to many Dom/mes (especially those who are very new to the d/s dynamic). Furthermore, I find it too common that inexperienced Doms have the assumption that submission = I will do whatever you want. It does not, and I most definitely will not. I have boundaries and will only even consider being submissive to those I fully trust to respect them. For these reasons, I decline accepting a 'submissive' designation prior to meeting.