Learning to Speed Paint

I'm teaching myself how to speed paint since at the moment, the technique hasn't been covered in any of my classes, and I love the style for concept art. Mainly working on environments right now since I can be a little more fluid with them; then hoping to graduate to more detailed projects.

Sadly, it's been a while since I have had the chance to do any drawing; but it feels good to get back into the swing of things!

All critiques are welcomed. =)