I've been trying to nail down the 'final' design for Donna, and think I've gotten alot closer. I was really struggling to get her face right, so spent literally a day at my computer studying her facial features and drawing some of them. I've now got a folder with over 100 screenshots of her pulling faces and looking decidedly...strange, which is great because I can just go in and find reference!
Here are some attempts before I referenced, and as you can see, I have either avoided the face completely or just suggested a face it there.
These next images I used a few sketches I'd done earlier in the project, and took a few poses I liked. I attempted her face but didn't feel they were successful.
With all these attempts looking not quite right, I went and got my reference, and some of the drawings I did of her I really liked.I started with some more realistic drawings of her, and then tried to subtly exaggerate the eyes like I have with the doctor.
I'm going to finalise Donna now and get her to fit in with how I want the Doctor to look. Obviously I can't use these realistic faces as I want the characters to be simple, 2D characters, but will find the reference helpful so she's simplified, but still recognisable.
Here's a page of scribbles I did to get some of the Doctor's expressions. I might do a couple of pages of referenced images again like I did with Donna. I also want to make him look older.
Oh, I also drew some cars for the collab, which I think will be used as an overlay: