My list of containers abounds that I've used.
When I first started, I looked in vain for one of those BCB tins that Lefty wrote about in his book.

Since then I've used:
Altoids tins - impossible to keep dry
Plastic Sucrets box - almost as bad but too thick
Zip loc baggies - not durable but replacements are cheap!
Pill box - not 100% waterproof but not bad either
Fishing lure box - not 100% waterproof but not bad either
Bulk film canister (I used to roll my own b&w film from 50' and 100' rolls back in the '70s) - not waterproof and too large for pocket but makes a pretty good boiling container
Lock'n'lock food containers - waterproof but bulky
1040 pelican case - waterproof but very bulky for the volume

and today I use the Ritter PSK pouch. My problem is that after many uses, it doesn't want to stay 100% closed now so either I find a replacement pouch or another container.