I too mark my ammo cans with tape and Sharpie, as far as caliber/gauge. I then place a slip of paper inside with current round count in the can.
I inventoried all ammo before the election.
I keep an updated list/count on primers and powder, on hand, in my smart phone. If I am out and about and come across a deal on either, I can reference my list to see what I am lowest on, SPP or LRP, etcetera.
I keep a rough count in my cell phone of ammo and reloading supplies.
Just curious, anyone ever get a count of how many .223s fit just dumped in a .30 cal can? I've been too lazy to count a full can. It'd be close enough just to count full cans.