Yep, you have the idea. Just use more soil where you want the higher areas to be and less where you want the lower areas. You can also put soil on one side of flat pieces of driftwood or rocks to create dramatic ledges and cliffs. Good luck,
:iv seen some terrariums where the landscape almost looks like "rolling hills" where the land comes then falls back down and rises back up.
:How do you do that? just pile the substrate up in the areas and form it to your liking. this may be a stupid question but i was wondering if there was a special way you do it.