If you're a heavy smoker (of a pack a day or more), we strongly recommend going with the highest strength, which is 20mg.
Moderate smokers should consider a strength of either 20mg or 10mg, and light smokers can likely get away with using 10mg or 5mg nic salts.
Please note that these are merely suggestions. Everyone has different tolerances, and you may find that you need a higher strength as a light smoker, or vice versa.
It's important to ensure that you're getting enough nicotine to satisfy your cravings so you don't go back to cigarettes. This is why we recommend higher nicotine strengths to start with, as they allow you more wiggle room when it comes time to wean yourself off of nicotine altogether.
Remember, if you've never been a smoker, you shouldn't be vaping at all.