Both have been discussing some of the terrain ideas from Major General Tremorden Rederring's Colonial-era Wargames Page . . . which is actually not a "page", but an extensive website which is generally simply referred to as the "Major General's".
So I decided to post a few photos from games that show some of the terrain features that they are contemplating. (Remember to "click" on any of the photos to see a larger version.)
These not only provide great places for ambushers or snipers, but in line with the Major General's philosophy, they take up very little table space.
They are also very flexible as the second photo demonstrates. Here I've placed two back-to-back in the center of the table, with my other two on the sides to create two "mountain passes.
And finally, they make good backgrounds for photos.

Using the techniques shown on the Major General's "Building Construction Page", I took my figure bases (in my case, pennies) and planned the interior roof size to fit a few troops comfortably.
I then made a few houses to hold a few more troops, then a few large enough to "nest" the smallest houses in order to make some two-storey structures with room enough for more figures in some cases.
For texturing, I used "spackle" (not sure what the Brits call it, but it is the stuff you use to patch holes in drywall. Then I used slightly different colors of "off-white" to create different looks. I was careful however to make sure that I used the same colors on those buildings that I wanted to be able to "nest".
-- Jeff