Here are some sketches you may find interesting (no pressure). These are the rough thumbnails I drew a few years ago for the publisher I was with at the time, when presenting my cover ideas for Mockingbird: Nightmare on Another Planet.
Here’s fun – why don’t you try to find the cover I ended up using? A firm handshake and solid thumbs up for the winner!
Postscript: Feel free to tell me if you think I should’ve used one of the other options, I won’t be offended. Hey, it might even start a fascinating discussion thread (I’ve seen these on other blogs!).