First, the thumbnails. Number 6 was chosen with the adnotation that the dragon should be a familiar, not a mount.
This is the sketch I came up with. Not entirely finished, but I usually add the details when inking.
Picture removed to save bandwidth. See below.
First of all, I'm sure there are errors I didn't notice, so crit away. Second, I'm thinking of attempting full digital on this (without inking and without the lines showing in the end), but I've never done that before, so I have no idea how it'll turn out, especially with me using a mouse. I might ink it anyway, just for the fun of it, but for now, I need to work on the sketch. Fire away!