The idea came to me when I received my Mega Minis "Salvage Crew" and I thought they need something to salvage, duh that's a no brainer, So I first thought why not a crashed spaceship and how was I going to go about this. I figured it had to be in sections for ease of moving it around and then how big, after all it's has to fit on a small gaming table and what sections, so I came up with the idea of four sections, a bridge section, two cargo sections and an engine section.
Based off of this picture
Then what shape to make it in. A box or square sort of shape with square edges and an angled hull would be the easiest to make and to cover it in card stock, then it would to make a round rounded with lots of curves and bends, hey mama didn't raise no fool.
So something like this comes to mind but in four sections
I sketched up the sections on 1/2 inch grid paper to get a feel and the idea of size. http://www.printfreegraphpaper.com/
Four separate sections, for the main hull and two wing like sections, each section could be used as stand alone terrain piece or put all six together as one big terrain piece with room to move between each section and space for movement in and on each section.
On 12x12 inch MDF board would allow it all to be on a 4 foot table or spread out over a larger table
I can dress up the shipwreck with tips from this link http://www.happinessismandatory.com/misc/Tutorial/ and download PDFs referring to scratch building.
Plus I can build up the interior walls using some of the ideas here http://www.bolterandchainsword.com/topic/251905-scratch-build-bt-thunderhawk/ can make the inner walls looking something like this picture from the link above.
This site is more for the War Hammer 40K stuff but full of pages of great ideas
A visit to my local junk shop where I can get all kinds electronic stuff cheap. should help dress it up nice, you would be surprise how a hand full of electronic parts can dress up a wall and make it look busy
Foam core board and card stock will be the main material, with lots of wire and wood dowels of different sizes plus different wood flat and round shapes, beads and bits from the local craft shop.
Craft gems from the craft store, based on size the square ones, the oval ones and round ones make for great hatches and other odds and ends