Step 1: Building It
The spacers are different for each drill. I could have shaped them like the profile of each different battery, but I didn't bother, and it isn't a problem. If the spacer has the right size, the drill body rests nicely against the edge of the hole.
I didn't fasten the plate or the spacers. It isn't nessasary, and this way I can easily make changes if a new drill comes along.
I played around with finding a good angle for the plate. If closer to horizontal, the drills can be stored in a drawer.
I saw many examples of drill storage where the drill is hanging from a plastic pipe or a cut-out in a plywood shelf. But i wasn't sure about this idea, because the direction switch would come in the way, and maybe get damaged.
Step 2: Accessory Bar and Chargers
Recently I added a simple accessory bar a the back. This way I have my most common accessories available right where I need them - when grabbing the drill. It's just a 15 mm piece of plywood with two rows of holes. One row has a 3 mm strip glued under the holes, so bits won't fall through. The upper row is for accessories that are longer and can hang the hole. Second picture shows how my charger (two drills use the same charger) is stored under the shelf. Third picture shows how I have put it in my shop. I put my most used drills in a block on the right, and another charger for my lithium batteries.