I am currently not in a position to buy commissions, but if I was I would definitely got for pin-ups or sketches. While some people feel fine with inserting their character in a YCH, I'm more personal with my own avatar, so I don't go for them. But they are popular for a reason, so don't let it deter you from dabbling in them.

I could imagine you could go about doing commissions as usual, and if you like some sort of sketch from personal art that you'd like to expand upon, you could put it up for auction in a YCH...if you wanted a business model of sorts.

Just opinions, hopefully they're helpful to you. :3

Not that this is relevant to feedback or anything but... Yay more arts ^^

I'm probably not typical since I don't get pinups or adult art. I tend to prefer sketches unless I have an idea for a more complicated illustration, then I tend to look for an artist whose style would work well for that idea. Sometimes I get an open slot from an artist I like and then try to come up with an idea that works for their style. I haven't gotten a YCH of my 'sona, but if I did it would be because I liked the pose or scene of the YCH. Since I can be detail oriented I usually try to find artists with the time and patience to work with me (especially if I think that others might use the artwork as a reference).

You could consider drawing a sheet of simple sketches that people could pick to be developed into a full picture, like a page of basic YCH's or concepts.