The mountains and hills were all done with custom brushes I drew. For the mountains I probably had about 20 brushes in the end but only used about a dozen (the rest of them were bad I guess, they never looked right when I placed them). The hills were the same although there were probably less brushes made and used - probably about 10 regular ones used. If you knew the order I did the hills in you could probably see how they become slightly more varied as I added more brushes.
I found making the brushes extremely tedious as I did them with the mouse and it gets a bit soul-destroying having to try and draw another curve that looks ok and then try and shade another large swathe of brush with my non-writing hand. :s So because of that I'd add one or two new ones every few days, hence the hills done at the end having more brushes used.
Personally I think the hills look more varied than the mountains anyway because the only way I could get them to look half decent in my mind was to do the shading between the brushes which make them look more hand drawn.
If/when I do a zoomed in map or maybe another continent in which another story (I once started and never finished
) takes place, then I'd LOVE to get myself a tablet and make a better job of the mountains.