Here are a few tests of different styles for rendering hills.

Here are the classic icon-based hills, which is what I think I'll stick with:
tutbad-test-7-hillicon.png

Here's an attempt to recreate the hachure-based hill markings seen on maps from the early 1900s. I think it turned out well, but isn't a fit for this style of map.
tutbad-test-7-hachure-s.pngtutbad-test-7-hachure-shade.png

And here's some sort of Mario-looking thing:
tutbad-test-7-stairsteps-s.png