I had to consider how much vaping was "too much" -- I have asthma, so anything I breathe, I have to consider very carefully. I quit smoking with 6mg, because I really needed to do it constantly, and if I vaped constantly with anything over 6mg, I got nauseous. Ugh. Once I had quit, I needed to go up a little, to 8mg, but I was still doing it constantly, so I went to 9mg, and it seemed to help, I could put it down sometimes.
After I recovered from my smoking relapse last summer, I started right out at 10mg, and stayed there for almost a year; recently I got an Achilles RDA which delivers such intense TH, I went back to 9mg. At this level, I *can* chainvape if I really want to -- watch TV, riding in the truck, etc -- but mostly I don't really feel the need. I'll have a hit or two, maybe 3, and set it down for a while -- till I really feel like having another hit or two.
If it makes you feel sick, dizzy, headachy, jittery, it's a bit much. Otherwise, just go with whatever feels right, in order to not smoke. For me at first, that meant constantly, but I didn't want to keep doing that forever.
Andria