I mix in several different proportions and nic levels for different devices. My standard for Kayfuns and rebuilt PT2's is 50-50 PG/VG at 1.2 mg/ml nic. For my drippers, I mix either no nic or .3 mg/ml and usually 70-30 VG/PG. I just can't take the throat hit with the extra nic and PG.
Generally speaking, more PG in a mix will carry more flavor, reduce vapor production, and provide a stronger throat hit. Nic content will also add to throat hit. When I mix higher VG content juice, I up the flavor % slightly as VG doesn't carry flavor as well as PG does.
I have found that using 100 mg/ml nic base in 100% VG carrier offers me the greatest flexibility when mixing, as most all flavors you will use are PG based. I can also mix at any nic level, and it is the most economical way to buy nic. Good luck with your mixing, and welcome to ECF!