I'm ediitng a lot of exterior locations in my current mod and am running into all sorts of issues with ground clipping. It seems nearly impossible to place a structure on the ground without any noticable clipping, without first flattening the entire area. Even then, I run into problems where pieces of the mesh are just floating and it looks pretty terrible. For example, the stocade walls that line the orc longhouses, because they have a large portion of their mesh that must intersect the ground horizontally, I find it difficult to place them on slopes or inclines. Does anyone have any tricks to make it look not so wonky or make the process a bit easier?

Use the raise / lower landscape brush in small increments...5 - 7units, size 9 brush. When you get it roughly flat, use the smooth vertices option. Just use single clicks. Holding the mouse button is too severe. Eventually you'll get there.

You could also place cliff statics at one end to make it look like it's built on a rocky outcrop. Play around with the landscape tools, but be very gentle.

you can also use platforms and buried buildings to create level ground where there was none before. And then, optionally, clutter that up to hide what you did. I've got this lovely bandit stronghold perched more or less on the side of a cliff. It works just fine.