If I understand what you’re getting at, this is often personal preference!
I tend to like a top-down approach with WM; working on small details when the big stuff is not finalized yet can be counter-productive as many times your fine-grained masks will depend on global operations, so getting them just-so and then changing the big picture can be frustrating.
So my workflow would be:
- What do I want the terrain to look like very coarsely? Flesh it out with a Shapes device, or large scale noise if random
- Start working on medium-scale (regional) features. This is where using multiple noise generators for different terrain areas, filters, erosion, etc comes in
- Add in any specific features (level areas, roads, etc) once the above are mostly complete
- Work on texturing and materials
And of course you can always go back and change stuff in step 1 late in the process; but proceeding in that fashion helps me get what I want most efficiently.