I've attached three pics - One is the pockets idea and the other is a second impulse buy rack (once you see that you'll get the poster board), this one shows the rack done with bubble wrap. I've had an added thought (and yep my project for the weekend is to REORGANIZE! just desperation till I can get a building
). I could put small holes above each pocket and then a large loop of a zip tie or something of that nature looped through the holes that is above each pocket, this would give added stability for the rods standing straight up. There is some glass in the cabinet, but I made sure to put any heavy stuff on the bottom shelf for stability of the cabinet.
Also note that I have pockets (believe its 2nd or 3rd row for frit (I have so much frit) - and if you look closely at an empty pocket you can see the outline of the cup.