Howdy
@kennybo. Welcome to the Vapeland Zoo.
VG/PG Ratio:
70VG/30PG- Generally speaking, higher VG will produce more vapor with a soft fluffy sort of sensation to the vape. Less "throat hit" with higher VG blends. BUT nicotine level also affects throat hit. VG is very thick, the higher the percentage used the more likely you are to have wicking issues. Some folks (I'm one) have a low tolerance for high VG blends. Can make us feel just as bad as smoking did. (Short of breath, heavy chest feeling).
30VG/70PG- (My preference) Higher PG will produce less visible vapor. Harsher throat hit. Supposedly carries flavor better. Wicks better.
Nicotine Ratio:
Can be confusing. The majority of vendors use a mg/ml measurement. Some vendors use a percentage measurement (usually convenience store juice).
I use a 30mg/ml ratio which is pretty high nic level. But I use low power vape gear. 30mg/ml is the same as 3%.
Sub ohm Vapers use much lower nicotine levels due to the intensity of the vapor produced by thier gear. An "average" nicotine level for sub ohm vaping would be 3mg/ml.
3mg/ml would be equal to .3%
Hope this helps.