Toolboxes, just grabbed some foam blocks, cut them out to size, for the upper trays then cut out holes to slide infantry in. Most CWE/DE infantry fits in those slots standing up.
Base of the tool box was big enough to stack two foam blocks on. So I can pile in a couple of Waves, 2 war walkers and a couple of Fire Prisms.
So thats, 40 troop slots (CWE/DE/Necrons), 20 bulky troops, 4 tanks and 2 war walkers.
I have a couple of other cases, one is mostly for Jetbikes and thin mechs, hornets, Nightwings, Wraithlords, etc. Where the last is for big things like the Wraightnight.
The laser cut foam from KR, battlefoam etc are great, but expensive. Especially if you have mutlple armies, but even if you have a single sizable army and change your roster around.