need some tips on how to make natural heightmaps

[su_liam]

step10.jpg
Whoa. A bit much. Lets try reducing opacity on the top layer a bit.
step10-1.jpg
Best I could do. Not great. You can see I haven't done this in awhile. But the ridge on the far left and the mountain at the bottom came out pretty well.

Changing the gradient map a bit and setting the hillshade's blend mode to soft light had good effects, I think.
step10-2.jpg

A bit of experimentation and you could do a lot better than this. I'd tone down the parallel ridges a bit. Some were clearly too high.

I did try adjusting the colors a bit with that last image.
(step11).jpg

Not great, but not too bad. Could be used as a hillshade layer in its own right. This took about two hours of which about 45 minutes was spent actually working on photoshop the rest was adjusting Save for Web, saving uploading and writing.

With a bit of practice and less time spent trying to explain the process you could likely get some good ridges in about half an hour. Better results could be had if you build up your terrain in layers(Man I wish Wilbur had layers or at least that the Apply Image filter worked with Virtual Terrain .bt).

Edit: Had a try with better sketch work.
final-try.jpg