I have a 6 foot long trophy case that is about 18 inches deep with 5 glass shelves. I have full sets on top, next shelf down is all the individual stickers not put unto full sets, next down are the display boxes that I have opened up and full of packs like they were in the stores, next down are the nicest example of each display box I could find and finally the bottom shelf has a shipping box the unopened display boxes came in. Then the right side of the case has the more odd stuff... the OPC versions, graded stickers and packs, fun pack and the sort.
That being said I only collect the 1979-1980 Reissues because that is when I found out about Wackys, therefore I have less stock to display than most here.
I used to have the entire 1-16 run a few years ago and I built a 3ft by 4 ft wall shelf that was about 4 inches deep and had a hinged door on the front that was thin clear plexiglass framed in wood. I would put the entire 1-16 series in there in sets and saving the middle shelf to display the individual rare stickers.