If you can get to an IKEA, they have these metal attachments that can be put on their standard shelves to be able to tilt them (ie. stopping things from sliding off). That's what I do. If I didn't explain it clearly enough (I wouldn't be surprised), I'll be making a video of my collection soon
You should first decide/explain what kind you are looking for. I keep mine in framed/glass front cases hung on the wall, some I bought, some I made (see my collection thread link below for photos, it's the 2nd one). Some people like them more accessible and don't need them behind glass so shelves of various types like have been mentioned might be better. Others prefer portable cases, others have so many freaking decks they use things like old paper index card catalog furniture or old blueprint dressers to keep them, etc.
There have been a number of threads and discussions on that (use search), but knowing what you are looking for would help point out options for you.