Deserts and grasslands make perfect sense being near each other. Grasslands are often caused by being too dry for forest so they make sense being near deserts.
Originally Posted by Hannibal.Lector
Forests don't need to be near mountains. It's just that those in mountainous terrain are less likely to have been cut down by humans than those on plains. Most of Europe was once forest for instance.
Really the relationship between forest boundaries and river lines is to complex an indirect for there to be any particular rule. I was just trying to point out how odd of a co-oincidence it is for all the forests to have rivers running the entire lengths of one edge.
There are various different symbols for cliffs. A line representing the cliff top, with little perpendicular lines sticking out to the slope side is fairly common.
If you want a purely decorative effect for the entire coastline, I'd recommend against a "raised" look as that sort of thing usually makes it look like the land is floating. Stipples along the coast might work but it's troublesome to pull off (I've put a lot of work into it). I usually put them in the water, but they can work on land too. Offset lines in the water are a simple, unobtrusive coastline effect that's elegant and easy to make.