Great, thanks. I'll watch through the video later. Someone linked his video on eyes elsewhere on the forum recently and I found that to be very good, so hopefully this will be too.
Just as a general point, where would you say my main weakness with the proportions is? I'm planning on going over them in a redraw just to make the corrections that I think are obvious, but I'd be interested in another pointer.
You're probably right about drawing less and taking more time per head whilst relying on references more. All of those are from imagination and I think it's apparent that I still don't have a full grasp of the construction as I keep imagining them with the same mistakes!
I was struggling to identify where the side plane initial circle exactly fell with my previous drawings from reference though so consciously moved away from it to avoid the frustration. Rookie error I think.