really enjoyed looking through your sketchbook, you're working on some awesome stuff: my favourites are the last one in #45 and post #59! lovely stuff, different too!
I'm also highly jealous of your 30 secs. posemaniacs: I'm still on the 60 secs. myself as I just can't get them down any faster!
I'm new to all this so i don't feel I can crit you, but it looks to me like your working on all the right things: anatomy, gestures, tonal values colour etc.
Keep them coming!