Let's say that you have some 15mm troops - for instance, a Royal Horse Artillery Battery - and you want to find an inexpensive way to store and transport them.
I took a suggestion from the TMP forums, and ordered some "pizza boxes" from uline.com. The technical term is white literature boxes, and they come in a variety of sizes - I decided on 12" x 12" x 2".
I also ordered some magnetic sheet. In my case, I ordered a giant roll of the stuff (2' x 50') from Renaissance Ink (probably enough to last a lifetime!). The roll is 24" wide, and I needed a piece slightly less than 12" x 12" to cover the bottom of the folded-up box:
Now, I needed to slap something on the bottom of my British troops, so that they would stick to the magnetic sheet. Fortunately, Litko makes a range of FlexSteel bases to match the small, medium and large Flames of War bases.
So now all I needed to do (in theory) was to clean off any crud that might be on the bottom of the existing bases, slap on an adhesive FlexSteel base, and drop it into my storage box.
Well, it was almost that simple. It turned out that the large and small FlexSteel bases were a hair too big - about 1/16" of an inch. I pressed them into place, then trimmed them to size with scissors, taking care not to scrape off the paint or texture from the painted base.
Also, it turns out that the Battlefront vehicles I had with cast-on bases are in-between the small and medium base sizes, and differed slightly in size from one vehicle type to another. I suppose I could have just stuck a "small" FlexSteel base in the middle, but I chose to use the medium bases and again trim to fit.
All in all, this took very little effort on my part, and I have storage for all my based 15mm British troops. But I still have some loose unbased vehicles... hmmmm...