When you move into the Cave you are welcome to pimp out your locker however you choose as long as it doesn't compromise the integrity of the locker. How people choose to store their wine is as diverse as the wine they store. Most keep it stacked in boxes which helps keep things snug and protected during earthquake. Most have some kind of basic shelves in their locker, cut from a sheet of plywood and set in on a few 2x2's. Others prefer no shelves to maximize space.
A few people like to break their wine out of the boxes and store the open bottles. This way they can just come in and grab what they want without having to unload half a locker looking for it. This is where the shelving can get a little tricky.
TUBES. You may have noticed, in this recently posted photo of Gil, his very cool locker set-up, a combination of shelves and tubes. I think his are cardboard, but you can go cardboard or PVC pipe. They are double deep, so he can pull out the front bottle to get to the back. There is currently an 18-case locker available that has some of these tubes in a bonus space, allowing for 20 cases.
Wood, some assembly required.
A gentleman recently moved and, sadly, cleared out his locker. He had an 18-case locker with these inside, double stacked, 17 notches tall and three across. A single 12x12 can go from $25 - $60, depending on where you get them.
Basic. Of course this is more my style - easy, simple, basic. Last weekend Janet came in with a few friends and installed these shelves into their 24-case locker. They had come in and measured everything previously so all the wood was pre-cut and ready to go. They made a spacer so they wouldn't have to measure anything, very smart. The shelves were built to accommodate bottles stacked three high. Every shelf has a placard that designates its genus. There was, I hear tale, a bottle of white wine that didn't fit anywhere into the system and so had to be "eliminated."
I have since seen this in another, 12-case, locker. It looks good, and it's clean, easy, and efficient.
I don't have a photo of it, but I know Chris has shelves that are a good compromise - basic shelves on the bottom for boxes, a basic diamond box in the center, and narrower shelves on top for additional bottles.