Low cost future terrain your recommendation.

[eilif]

Fair dinkum, but you can find some crates that will nest a bit.

The ones I want to use for '15mm' could be small, cramped buildings at 28mm, and if you turn same sized crates, the nest a bit as well.

And even if they don't, they're CRATES. Fill them with other terrain pieces... 

Doug

(whiny voice on) But I like the big ones! (whiny voice off)

Seriously though, for the size or nesting isn't really a big deal. I nest one sideways inside the other put each in a plastic grocery bag and put them all in a big blue IKEA bag that I store by hanging it from the ceiling in my workspace.

I love IKEA blue Bags. Big, handy and nearly bombproof. I've got some I've been using for the better part of a decade and they are still going.

[nic-e]

I love IKEA blue Bags. Big, handy and nearly bombproof. I've got some I've been using for the better part of a decade and they are still going.

Those bags carried my stuff to dorms and now serve as my wash basket and material bag for getting stuff too & from uni.I think ikea should get some sort of product design award for them.

[maxxon]

Let's see...

Piles of stuff under tarps:


That's just random crap covered with tissue soaked in PVA.

Furniture:


Just cut lengths of wood, stick on a few bits of card and paint.

Oil tanks:


They're just tin cans with a few gubbins tacked on.

Pipe stacks:


Real easy to make from any plastic tubing you have handy.

Plaster castings:


I used the packaging for easter eggs as the mold. There's a video of the whole process.

More examples of plaster works:


Don't throw those packing materials away just yet! These were done using the plastic packaging from those stupid Battlefield Evolution vehicles.

Woodworking:


That's just some planks and hardboard. The columns are dice boxes.

Barrels:


It's those things you get inside easter eggs. They're in groups of three for stability.

Cheap isn't necessarily free. But your gaming dollar can go a long way shopping at the hardware store instead of specialised modelling shops. A layer of paint does wonders (and DON'T use modelling paints).

Just one word of warning: I've seen way more bad pieces of terrain done using styrofoam packaging than I've seen good ones. It takes a lot of work to find shapes that are actually usable and to hide their styrofoam texture.