/ic/ - Artwork/Critique

I'm doing these rough renders trying to get a feel for what the process should be like, at the moment I'm just putting colors down and seeing what sticks. Not sure how to give it depth and make it less muddy. Feels like solid brush strokes are too hard but blending them together makes for an airbrushy look. I don't know the first thing about rendering, like if I should keep layers separate, or if I should paint from darkest to lightest, or if I should rely on blending modes. I have had some success in the past with doing values first and then adding color, but I don't want to do that.