Welcome back, I am glad you are finally situated in a new home! Now, I of course am not as good an artist as you are, but I will do my best to help:
Draw whenever you can. I try not to go a day without drawing, maybe you could spend your spare time improving.
I really don't know what to criticize, maybe you could draw hinged mouths to make them more accurate, but I think it looks fine the way it is. You could also add little features from the sets on to your drawings.
-TT-