I am not sure you can, I think the initial "buzz" might have been from the increase in nic, or higher nic than you were used to. Your body has become tolerant to nic, so you'd either need to lower and/or stop for a while, or raise your nic FURTHER which I am NOT recommending by the way.
I have never, not ONCE gotten a buzz from my vapes. I don't seek it out either, I was a 3 ppd smoker and never really got a "buzz" from that either. I vape 18 m.g nicotine, but frankly given my tobacco consumption if anything, I likely DECREASED my nicotine levels. I was looking for a level that would "work" and not cause me to crave cigarettes.. Etc. So, I don't think you are going to get what you are after.
Still I guess my advice would be to stop for a while. Probably about two weeks. You may or may not get your "buzz" back, and it may or may not be there as LONG. Much as muscles have memory (they can often do things after a break because they "Remember" how) so does brain homeostasis. My guess is that any "buzz" you'd get would be FAR less intense, less frequent, and less strong and last less time. Your brain is now "accustomed" to that nicotine level and every time you stop and return, I am going to guess that your brain will sort of "recognize" that level sooner. Etc.
I quit smoking for 18 months cold turkey (pregnant and nursing) and I really only remember having two or three "buzzy" cigarettes, my brain "recognized" tobacco. Most folks have similar experiences.
Anna
