Scifi Environment No outline

I've taken the outline that I sketched out the painting now and its working well. Just working on getting the colours right for the painting at the moment, and see what works and what doesn't.

I am finding that the top painting does not have that much in contrast at the moment, and this is something that I need to work on as I get on with it. The Ice cave one seems to be working out well at the moment, just need to fix some lighting and need to add in some references to lights inside the building. The desert one is going okay, I feel that I need to change the contrast a bit as its too dark in places and too light in others. 

I found these two tutorials very helpful and made me want to play in this way because I can take myself away from one painting and then focus on another. Giving my mind a rest and being able to think straight. 

http://www.artbyfeng.com/tutorials.htm

http://www.artbyfeng.com/tutorials.htm