I'm really liking the texture work and detail in these speed paintings. The white sky gives it quite a striking composition, but I wonder if it might be a bit too bright -- hiding something in the far background. That said, it directs the eye to the towers and mountainous landscape. I like the level of detail given that it's about an hour of work on your part. Very nice!
Yep, when you don't have to mess with colors and only values it goes really quick. In mountains, there's a lot more contrast and you use that to indicate snow with a simple brush that does some texture. You mainly have to have your values right.