I always make an unflavored base with nic, then if I want flavored juice I simply add flavor to small batches of my base. I vape 60 pg / 40 VG, and shoot my batches in 100 ml volumes to ease the process. I have a 100 ml graduated cylinder so this makes life very simple, I can even do it while inebriated without fear LOL.
The following is for 6mg/ml - 6.5mg/ml, for whatever nic value you need, simply adjust the mls drawn to match, like for 3mg/ml, you draw 3ml of 100 mg/ml, and adjust your pg or VG to compensate for a 100 ml batch...
So for 100 ml of base, I will draw 6-6.5 ml of 100 mg pg nic, and dispense it into the bottle I will be shaking it up in. Then I will pour 40 ml of VG, and the fill the graduated cylinder to 94 ml with pg. this will give me the exact amount of every thing needed in a very simple single measure pour,, the cylinder gets poured into the mixing bottle...I usually use a 16 oz tumbler to rest the cylinder on with the spout of the cylinder resting on the mouth of the bottle to allow all of the VG to drain. If I'm making 200 ml batch, I simply repeat the above process to accommodate. When everything is in the bottle I shake it for a couple minutes and then take my syringe that I measured the nic with, and repeatedly fill and plunge it into the mixing bottle to rinse it of the 100 mg nic.
I've never used a mixing calculator, and whenever working with odd volumes of ejuice, I prefer to do the math myself, on paper, and double check my figures with an electronic calculator, for my piece of mind, I need to fully understand what I am doing to be comfortable with it. It's a quirk...
