Well, first it is good to get yourself a foundation. Like, what will you be willing, and wanting to draw? Then try and "get your own thing" going. Then decide if you want to do generic stuff, or more unique stuff.
While generic might seem "easy" to do (ex: blowjobs) one has to keep in mind pretty much everyone does them. So aiming in on, and narrowing down on something would be really efficient. Like, going with recent stuff: Perhaps take aim for bondage. Then perhaps try to be as "open" in said area as possible, as it wouldn't lock you with ex: just getting asked to "draw more blowjobs". While some are fine with that, it does really stagnate ones art. So in those terms, if ex: bondage was picked. Narrow out what types you'd allow/draw, eventually think what you would be willing to draw, Since being willing to draw ex. both males and females tied up would be more "versatile" than just doing females. As said, depends how much you are willing and aiming for to be able to offer. Hope that made sense, a bit tired writing atm heh.