I realize the difficulty in using such a granular system as the TerrainLinX system to create organic shapes, but I think the addition of the triangular half-tiles, along with using an organic texture on the walls and floors, will go a long way toward handling this problem.
I might start on this as early as tonight, though more likely it'll be tomorrow, and I'll definitely take pictures to let you guys see how everything's coming together.
Magius out.

I don't quite see what you'd need triangular tiles for. You can just use normal tiles and then set up angular walls.
Or do you intend to use the triangles to top off the upper part of the hill? For example to build a hill with an octagonal footpring instead of a square one?

That's exactly what I'd use them for, especially what I'm referring to as the 2/3 triangular pieces (basically, cutting diagonally just after the glue point for the anchor so that I can use it on the middle level instead of just on top). This will also add some flexibility on the base tiles without having to create strange combinations on the base tiles themselves (for example, instead of making a tile that's half grass and half stone that's split along where the wall would go, I can just use a half-piece of each). For a standard building, I don't think it would have much of an impact, but it would go a long way toward giving a more natural feel to a natural wall.
The only issue with this is the fact that the 2/3 tile would overhang the wall below it a bit, while the 1/2 tile wouldn't cover all of the post below. Then again, that's why I'm including both.
Magius out.

I've been thinking about different ways to do hills and such. I have an alternate idea for you (take it for what it's worth).

I'd make the hills Hellworks/Mars Station style, where each piece is it's own organic shape/style. Then I'd simply cut holes (somewhat randomly) in the bottom that could be place over anchors, similar to the bottom of the Large Columns from Lost Halls. On top of the hills I'd pull anchors so that structures could be placed. Alternately, the hill could simply be glued to a tile, or the bottom could be left open, and posts could be mounted along the side of the hills

For larger area hills (ie, bigger than one sheet of paper across), just square one or more sides so that they could multiple hills be linked together along the squared sides, perhaps underneath by bobby-pin, or by some clever as-yet-to-be-determined Tlinxy method.

While that's a workable idea (and just about exactly what I'll be doing for the Stalagmites), I wanted something that I could fit in with other TerrainLinx pieces seemlessly - so you could build a Dwarven Fortress built into a cliffside, a cavern worn out by a river passing through it, etc, etc. While that would create a very organic look for the set, it wouldn't allow for as easy a transition as I would like.
That said, I will be trying out a couple of things to ease the transition - 1" tall connector posts and walls to give a more gradual slope to the terrain, and slopes modified from the Thoumont's roofing system to give the illusion of a gentle slope and give a less straight-line footprint - but I haven't even started on the easy stuff yet (walls and such), so all of this is just sitting in the back of my head for the moment.
Magius out.

One thing you might consider for an organic look is simply making the walls bendy. For example, for a normal 6" wall, print out the long angled wall, and bend it back and forth (either in curves, or hard angles, depending on the surface you're trying to emulate). If you connect enough of these (most on posts to anchors, but some posts could be free floating), the area will look to eye as if its fairly organic, even if most of it is regular.

OK, as promised, here's the first round of pics. I'm just starting on the project, but I'm hoping you guys can see the potential of what I'm trying to do:

First off, what the half-tiles look like on the ground:


Next up, how the half tiles look with a wall and another tile attached. You'll note that it lies flatter when attached to another tile.


Finally, here's how the half tile will look resting on the top of the level below (I haven't finished that particular tile yet...).


That takes care of the first round of piccies. I'll upload the next batch when I've built up the area a bit (tiles around the base and some 3" dirt tiles to give the build a bit more variety on the base geometry). Until then.
Magius out.

OK, it's been a couple of weeks since the last update on this, but I'm still working on it. After a flurry of activity yesterday and today, I've finally finished some of the fun stuff - the slopes (well, a good start on them, anyways). I've also finished up the tiles for the demo build, and I have pictures of what I've finished so far:

First up, the basic structure without any slopes.

A second angle. Nothing too exciting yet, but this is the basic shape I'm going with (for now).

Here's a look at the build with a single slop put on.

Finally, a view of the piece with the slopes put on. This is about the same angle as the last picture, just with the two new slope pieces (90 degree turn, and 6" transition) in place. Now, I just need to work out all the details on building a 45 degree angle turn when the trusses won't fit together (without making it a 3 page build...), and I'll be good to go. I think I know how to do it (and if it works, it'll be the first TerrainLinx piece to socket directly into another wall piece), but I still need to design and build the thing.
Magius out.

NICE!!! I love how you've adapted Thoumont's TLX roofing to suite more organic, angular hill forms. Brilliant move!

Wow, I wasn't sure about this at first, but damn - It really came together very nicely! I'll be watching this with great interest! Especially since I've been wanting Hinterlands all T'lnxedified for awhile now!

Nice work!

That's a Great kitbash, Magius. TLX countryside = awesome!

Suggest you have try edging all the rest of those pieces, as all the white lines detract unfairly from what is an otherwise superb bit of work. Even if the color isn't quite right, it will be a lot better than white.
You'll get the best resutls by edging before assembly - easier to keep the edging to the edges. If I have to edge afterward, I use a chisel tipped pen (to get into the notch) and a lot of concentration. If possible, edge from the back side - that way any spillover is hidden from view,