Sandpoint Garrison WIP

[ravells]

I'm not sure why, but it doesn't look like a mound to me although the logic you mentioned is right.

I footled about in Photoshop (not sure if that's what you use), and got this.

What I did was make a border selection around the castle for the mound and saved the selection.
created a new layer, rendered some clouds and a lot of difference clouds for a marbled effect.
Used the pinch filter on the clouds
loaded selection and deleted the bits outside the mound, lowered the opacity and used a blend mode (I think it was overlay).
New layer, sampled the green of the grass, loaded selection and filled it.
Used a bevel and emboss layerstyle on that layer and played with the settings.

I'm sure you could get it to look much better with more work (this took about 10 mins), but basically the way I approached the problem was to try to get two effects:

The bevel on the mound,
The suggestion of erosion down the slope of the mound.

best

Ravs