Line Drawing. Really trying to ignore small details (really hard for me to do) and concentrate on the biggest shapes, or "groups of stuff". I'm not thinking "trees, mountain, trees on top of mountain, sky", more like "big triangle shape pointing down and to the left". I didn't even bother putting in the hillside bushes at this point, since I figured they weren't big enough shapes and not as important in making the statement I was going for at this stage.
Color block in. Really trying to not worry about color subtleties. In Kevin Macpherson's book, he suggests blocking in color like you are cutting pieces of colored paper into simple shapes amd pieceng them together. I'm really trying to stick to that idea. Cutting out tiny color variations and gradients would suck if you had to do it with a pair of scissors.
Detailing. Now that the biggest relationships are worked out. I just have to look at the subtle variations. Warmer, cooler, lighter, darker. I've given myself enough information that I've narrowed down the guess work.
I was thinking that painting landscapes are like describing a person in words. You start with the biggest descriptors, and work towards smaller details. You'd probably start with their height, skin and hair color, not the shape of their nostrils or mouth. Same with landscapes, at least for me. I'm trying to see the the biggest descriptors, like the shape and overall color of trees and mountains, not the individual blades of grass, rocks, or leaves.