I'm not mixing my own, but I do transfer what we get in some awful plastic bottles into the eye dropper glass bottles that we've cleaned and saved up since starting vaping, so I simply use a custom made label that I print onto Avery mailing labels. I didn't have to go fancy with my labels but I couldn't sleep one night so I sat up at my computer working on making labels that looked professional.
I'd show them but my wife and I have the desire/fantasy to getting into e-liquid manufacturing/mixing for sale if we can ever get a loan big enough to do it right so I don't want to give away our name or our new logo. Anyway, Avery labels are great as they have all came off cleanly when we have emptied out a tank and it's time to stick a new one on it.
Before we moved we used the Dynmo (or however it's spelled) label maker. Thankfully it was misplaced as when we first got it, the wife went crazy around the house labeling where everything needs to be, kitchen cupboards, check, bathroom, check, garage, check, My Home Office... Whoa... not so fast there little love.