Being new to this, I of course bought a ton of flavours and several tanks (of which I've added to almost daily, lol). And one morning I got up and found I couldn't remember what was in which tank.
First I started keeping each tank standing on an index card with the flavour and nic level written on it. This was fine until one of the cats decided to see if these new toys rolled across the counter well. That killed that system, lol. (The cats had a lot of fun, though.)
I happen to have beads in my house, so my next system was to tie a bead to an "o" ring and slip it over the tank (actually this was kinda fun as, depending on how crafty you are, you can make all sorts of cute little strings of beaded charms). I then wrote on one index card the colour or stone-type of bead and what was in the corresponding tank. So far, this system is working well.
How does everyone else remember who's on first and what's on second????