Right now I just have mine in baskets. Some are in bags and some in their original boxes, then put attractively in a couple of baskets I have. But now they've outgrown the biggest basket where I keep the ones I don't use as much, so I'm going to move them to a still bigger basket I have. The ones I use a lot I have in a black wire basket made to look like a spider web that has a big wire spider on the outside. In honor of Halloween, you know.
I've recently acquired quite a few tarot and other metaphysical books, too, and am going to have to rearrange my bookcases to accomodate them all.
I have a couple of cheap TV or stereo stands (not sure which) that I got for free that are alike. I moved them together so they make a kind of wall unit and I use them for my books and decks. There's a big area in the center where what was once two sides for stereo speakers, I think, would have been but now that they're shoved together, it's a big open space and in there is my big tarot basket. The area where maybe a VCR or movies or whatever would have gone in what used to be the centers of the two units I now use for book space. And on top, in the center, I put the spider basket. At each end are lamps. On the two open ends on each side where there's a big space, I've put a huge Buddha on one side and a very big Native American sculpture on the other side. Between the lamps and the spider basket on top are candles and smaller Buddha figurines.
When I can afford it, I plan to get two three-shelf inexpensive but matching bookcases to stand on the top of the makeshift unit so that it will look like a big wall sized bookcase unit, and then I'll find somewhere else for the decks in the spider basket.
OK, I'm sure that's way more than you wanted to know, but that's where I keep my decks, anyway.