Reddit gets drawn is or was a pretty nice place where people submit photos of themselves and you can practice drawing them. What I like about it is that it had a sort of disciplining effect on me - having just a day or two to finish a thing, knowing somebody will care about it (because everyone cares about their face) - it made me less inclined to get lazy and abandon work half-done. Also, I cared about getting upvotes and competing with other artists. And showing off, of course: "look at all the things I can do, I'm a chameleon".
The unfortunate part about redditgetsdrawn is, strangely, that it began to suffer from a shortage of photos. Not artists - photos. So often a day went by and hardly any usable photos were submitted. That kind of made me stop going there, eventually. So, if you want someone to draw you it wouldn't be a bad idea to go to the sub and post a picture of you, they are badly needed to sustain the place.