I've been collecting these coffee cans. They're the right size and I think they'll stack well.
I took off their lables.
I stuck them all together with some cool looking zebra duck tape.
I then sorted my markers by color.
The caddy can be used either upright, when I'm moving around with it, or on its side when I'm in my office. Probably, if I were doing this project again, I could do something a bit more sophisticated than duck tape but I'll see how this goes for now. So far, it's holding up fine! I also think it needs a handle but I haven't figure that out yet.
After a while, the duct tape started to loosen and the the caddy was listing to one side. I cut it apart and glued some cardboard inbetween the top and bottom cans to keep it stable. I wanted to glue them in the first place but the metal rims on the cans lifed them up just enough so they wouldn't touch. If I had it to do over, I'd use oatmeal boxes which have no rims. Still, it's functional in the way I wanted.