Here's a little tutorial on some 40k future containers that I made. Get a Mentos Cube Chewing Gum box [currently available in most Home Bargain/Quality Save in the UK for 59p]
Remove all labelling and take the lid off without breaking the sea;
After emptying the contents, preferably into your mouth, slice off all the protruding parts on the lid.
Add cereal box card reinforcements and undercoat. I've .pdf templates for the reinforcements if anyone wants to give it a go. All you need do is print them out, pritt stick or spray mount them to your card and then cut out with a craft knife or scalpel [watch your fingers].
Turn them upside down and add granny grating to the top, brass picture hooks can work as crane pick-up points, but you won't be able to stack them directly on top of each other if you do.
Stack 'em high. Probably big enough to hide a Tervigon!
Currently trying to paint them with some nice rust effects, will update when they're done. Note that some have extra reinforcements in the corner for variety. The .pdf template has these extra pieces, they're the centre reinforcements cut diagonally along the dotted line, good for half your container being ultra-strong.
Also if you take the lids completely off most poster tube end caps make ideal liquid-tank lids. Perhaps some of that square mesh often used as railings wrapped round and you could create something like these.
I'll get round to the half height .pdf at some point and updates of the finished painting as and when it's done. Hope you get some use out of this.