Been storing my nic in my freezer for years.
I break it down to 30ml bottles using a graduated cylinder.
Then set one out of the freezer a day in advance of diluting it from 10% to 3%. That equates to 100ml @3% which is plenty for final dilution and adding flavor.
My final product is mixed @1.8% nic, and the only equipment I need is a 100ml graduated cylinder, 3ml and 5ml blunt tip syringes.
Ejuicemeup software program will give exact recipe measurements.
Edit: forgot to mention I keep a dozen each 30ml & 60ml glass bottles for storage.