If you want to draw hentai, hear me out: furry yaoi amputees, blowjobs in wheelchairs.
Wheelchairs are so niche, I always try to encourage people to draw wheelchairs into their porn to give some visibility to wheelchair bound peeps. Imagine you're in a wheelchair your whole life, then suddenly you come across some artist that draws hentai with characters in wheelchairs. Do you know how validating that must feel? Do it.
As for "furry yaoi amputees, blowjobs in wheelchairs" I think that just came out of a repressed place, sorry :c