I use a 3-tray tackle box with lots of compartments. I bought a label maker to label my cartos, then I throw them in the compartment in the tackle box with the
juice. I don't have enough compartments to put all my juices in, so I only put my favorites in the trays and then put the other juices and cartos in Ziploc baggies and write the flavor on the baggie with a marker, and throw the baggie in the bottom of the tackle box.
I picked up a hard shell case for glasses at the dollar store and raid my tackle box when I'm going out and just throw a few cartos and batteries in the glasses case.