Right now I have one Mod Box, a Think Vape Finder DNA75c. I have 6 Siren 2 24mm tanks. I am trying out all kinds of coil variations. My short term memory may be the problem, but I can't remember how many wraps, spaced or contact, wire type, I put in each, let alone tell them apart. So when I find a tank is giving me better flavor, I would have to pull it apart to check to replicate it in another tank. I think if I were not in a tinkering and experimenting process, this would not be much of an issue.
At any rate, for me it makes my builds easier, and when I want a particular flavor, I can also just reach for it more easily. Perhaps I'm just developing ADD or early Alzheimer's, but I like the labels at this point.
I use an Excel spreadsheet. That way I can also see what juice is in which tank and keep track of how often I rewick and rebuild.
Ha, a spreadsheet man, that would be fun except I still could not tell which tank is which

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I keep a fully indexed SQL database containing every bit of data on my current vaping setups with 4 hourly backups to a RAID 5 array in a secure facility in my basement guarded by ex Navy Seal ferrets.
No I don't.
I either remember, or just rebuild it.
If I was to keep track I would make notes in a text file, I wouldn't ugly up my gear with sticky labels. Do you work for DYMO? This feels like an infomercial.
That's the ticket, I need a database! I would build a server for backups, but I'm the daring type and will just rely on hourly backups to the Cloud. The Ferrets are an excellent idea, but I'm afraid they might take to chewing on the wiring.
You got me on the DYMO issue, I got a lifetime supply of label cartridges for this post in every color they make so that I can add color coding to my system

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I use driptips and my memory.
Anna
Apparently memory is not a viable choice, but I could label the drip tips

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