It's amazing how quickly a few hand fulls of tiny gravel bits, miniature trees and shrubs can transform an otherwise unconvincing tabletop of foam.
As I ballasted the track, I started weathering it as well, using diluted brown and ocre acrylic paint. As I got the hang of it, I added static grass, shrubs etc., to areas adjacent to the track. Otherwise I'd have gravel comingled with the ground cover. So the two steps kinda morphed into a tandem operation. I even got up the courage to paint the stream bed.
I was pretty happy with things, as I ended this initial foray into scenery making, though I still had no idea what I wanted to do at the West end of the layout, where I'd left a flat, slightly elevated piee of black poster board, and a bare corner.