As another light smoker, here's what has worked for me and where I am going. I started with 6 nic, as I smoked about 7-8 Marlboro lights a day. The 6 worked for me and I was able to complelely quit immediately with some cig craving about once a day that I could vape through. I did start chain
vaping, and I didn't want to wind up MORE addicted to nicotine, so I lowered to 3. 3 worked pretty well, since I was over the initial quitting analogs, and before long I was eyeing 0 nic. So I started buying 0 and would boost it with a couple drops (or more) of a complementary 3 or 6 flavor I had in stock. By this time, straight 6 was too strong for everyday
vaping.
But now I have this whole confusing mess of various flavors and strengths and when I want to raise the nic a little on my Summer Sweet maybe I don't have the right booster flavor in the right strength, and I need to buy more 3 Vanilla Custard to go with the 0 Caramel Swirl... So I went with a big bottle of plain 3 nic and am buying all 0 flavors. This gives me flexibility with any flaovor I want to have between almost 3 and 0. I still have some 6 flavor if I really need to hit the sauce and will probably maintain a small amount of 6 in a flavor I can always vape to get me through the phone-throwing, I'm-going-to-quit-this-job moments. Point being to avoid having five flavors each in three nic strengths.
YMMV, but it's working for me.