There are many, many ways to make e-juice. In its simplest form, you can add flavoring to the NicBase and warm it then shake it. Here is an example of a single flavor e-Juice at 10% flavoring for a 20/80 (PG/VG) base ratio in a 30mL bottle.
- 03.0mL Watermelon Flavor
- 03.0mL Propylene Glycol (PG) Plain (No Nicotine)
- 24.0mL 6mg/mL NicBase Nicotine with VG as the Carrier Base
This recipe works because Flavoring is PG based and counts as PG in your recipe. Adding the flavoring and the PG together you have 6.0mL which is 20% of the 30mL bottle which satisfies the 20% (PG) side of the 20/80 requirement.
The Nicotine is VG based and 24.0mL is 80% of the 30mL bottle which then satisfies the 80% (VG) requirement.
If you want more Flavoring then reduce the PG by the same amount you increase the flavoring. To use less flavoring, reverse it and add PG to the amount of flavoring you are removing.
If you always balance your e-juice by calculating each side of the equation, then you can easily make 30/70, 20/80, 40/60... just remember that flavoring is counted with the PG on whichever side of the equation you use.