I think you have the right idea for the cliffs. But personally I'd make the ledges more continuous and maybe the descending lines a bit longer.

As for the mountains, I think the size difference is a bit too exaggerated. Not that there can't be a large difference in the scaling but as it currently is I think they look like they're from two different maps. I think a few shorter peaks mixed among the tall ones will show that the scale difference is intentional.

One way to get a bit more control when you don't have a tablet is to draw things by hand and scan them in, then go over them with the mouse as necessary. If you're using a laptop, finger painting with the trackpad can also be pretty effective once you get the hang of it.