1) Find a flavor of e-liquid that you like well enough to use regularly.
2) Start off at the nicotine concentration that most closely replicates your smoking habit (for me 18mg ~ 1.5 packs/day)
3) Continue vaping at each concentration for a minimum of 2-3 months to ensure you are fully acclimated to one level before proceeding to the next.
4) Slowly reduce the nicotine level over time by buying liquid with less nicotine in it. (I went 18, 12, 9, 6, 3, 0. I mixed a 50/50 concentration of 12 and 6 to make 9.)
5) The transition from 3mg to 0 will be difficult, as this is the step where you're really leaving the nicotine. It's ok if you're sucking on the vaporizer nearly constantly.
6) Once fully accustomed to 0mg, putting the vape down altogether will be the hardest part. I replaced it with sugarfree chewing gum. I was very angry for the first couple of weeks, but it got better.
For me the ability to separate the nicotine from the smoking and conquer each addiction separately was the key to success.