Warhammer 40k Terrain!

Hello folks!

With all the time I've had between games (and the relative success I've had at finishing my painting projects), my mind has turned to terrain. My store of terrain has played second-fiddle to my army itself for a long time, and it shows (my earlier battle-report posts show some of the stuff I've been using)

So, I thought I would do a quick look around to see what others are doing. I was hoping for tips on: technique, materials, and ideas.

First, for technique, I found an awesome blog on terrain building
These guys are really good, and they provide materials, step-by-step photos, and some basic techniques (such as starting your buildings with a layer of self-textured paint before base-coating them). Great site with a number of good posts, check it out!

Second, and for me, the biggest thing to find, materials. Once you have the right pieces and some basic techniques, it's a matter of just using your game experience and building something that would make for interesting play - such as a multi-floor ruin with stairs for squads to fight up and down, maybe on their way to take or escape with a Relic.
The link above recommended something called foam-core, which I'd never heard of. I've heard before of balsa-wood (my personal favorite right now) and plasticard (which is the most durable and thinnest, but hardest to work with) as well as the basics - empty cans, cereal boxes, loose wire, etc. All of this stuff is easy to find at hobby stores, or you can get decent deals on bulk raw supplies all over E-bay.
Styrofoam is also usable, although I tend to avoid it because it's very messy, on the fragile side, and it melts under spray paint unless thoroughly undercoated first. 

Sky bridges, bunkers (although I tend to find these uninteresting...), towers, walls - whatever strikes your fancy.
For a little inspiration, I just found this Pinterest board
I'm sure there are others, but this one was a great one to scroll through right off the bat.

For absolute beginners, here's a short list of tools I find indispensable:

Cutting surface (I often use an expendable encyclopedia/cutting board or very thick cardboard)
Small wire cutters (for trimming models, getting pieces out of sprues, etc)
Scalpel/Razor blade (for more trimming, and cutting balsa-wood)
Painting supplies (base paint, paints, brushes, water pot, paper towel to wipe off brushes, light)
Super glue (absolutely necessary for everything!)
Sand/Faux Grass (for basic basing)

For more advanced work:

Small drill (I use a dremmel with different attachments)
Airbrush for painting
Saw (anything from a decent hacksaw to those hobby saws GW sells)
Textured/latex paint (for undercoating terrain)

And that about covers it-
When I get the time, I'll post a few pictures of my own current terrain projects. But for now, enjoy the above articles/pictures!