Your shading is awesome, and I really really like the wierd creatures. Their faces are definitely unique (and some were downright creepy!).
This is a minor crit, but it bugged me a few times. It seems like when you do three-quarter views the far eye isn't always lined up with the closer eye. It seems a little skewed at times. Probably nothing a little attention won't fix.
And to answer your question I usually draw whenever I can, that is maybe two hours a day on most days (when I've got time I draw more). I guess that my goals are to learn how to make good illustrations and potentially do some sequential art.