Here's a recent sketch I did for someone . It's Kaylee from Firefly/Serenity. I have to tell you because it may not be apparent. I consider my artistic weakness to be likenesses so I was dreading doing this--I didn't want to disappoint the owner of this sketchbook. That said I think it came out all right, as in, I expected it to be a whole lot worse.
By the way, if I haven't said it before, I am a big Joss Whedon fan. If you've never got into Buffy or Angel I would still recommend the Firefly series. Oddly enough, this sci-fi series is probably his most accessible work. I know a lot of people who wouldn't normally like any "genre" tv who love this show. The whole first season is available on DVD and very reasonably priced. If you haven't seen the movie (Serenity) then I would recommend holding off until watching the series first as it takes place after the events in the series and wraps up some unresolved questions from the series. I highly recommend both.