What strength e-liquid should I purchase?

This is, in a way, the trickiest question of all because ultimately it’s a personal preference. You need to try out vaping to see what you like. Some vapers simply prefer a stronger nicotine e-liquid but on a lower powered device, whereas others prefer less nicotine but on a more powerful device. And some people are somewhere in the middle! Also, vapers differ in how much nicotine they need, and how much they want to vape overall. So, if you want to vape less, use a stronger e-liquid, if you find you’re getting too much nicotine from the amount you like to vape, move to a less strong liquid.