This thread is very relevant to my interests.
Not a fan of futa, personally, except for the purposes of comedy ("And now that you're my prisoner, Mokou, take a look at what Eirin's drug gave ME!") but these are really nice to look at. I can't draw to save my life, but I also recommend getting/stealing/borrowing a scanner, and maybe also putting more emphasis on shading. Apart from that, though, these are pretty nice! Keep it up!