Looking at the image component approach to concept art again. I’m doing a course on LearnSquared about World Building, and the tutor is creating custom brushes for architectural detail. Reminded me of a tutorial I have by David Levy, describing the custom brush approach. Basically use custom brushes to create a library of image components that one can quickly throw into a speed painting. Also Simon Scales was big on custom vector shapes, but basically the same idea.
The trees here were rendered out of Blender as masks for an XFrog tree, then turned into a brush. Learning how to do that should be really useful. The clouds and rocks were made by hand in GIMP, following David Levy’s tutorial. I used mainly the path tool in GIMP to draw a mountain following a reference image that I like, then turned it into another brush. Also I used a couple of standard GIMP texture brushes.
Most concept artists recommend starting with value sketches, so this approach definitely lends itself to that. With a library of elements it should be fairly easy to play around with scenes and compositions, which is the whole idea after all.