24 is considered strong and new vapers should not really start at 24 . Most of us do start at 24 because we feel we need to but that is not true . Get them to start at 9 or 12 then they can go up from there if that does not satisfy them .
This is some of the worst advice I have read on ECF. The vast majority of people trying to transition away from smoking and to vaping, need around 24mg to make the transition. 24mg is the most common strength vaped based on polls on ECF and other vaping forums. There are some who are successful using lower levels and that is fine, but they are far from the majority.
There are many people who started too low, decided that vaping was a "scam" because it didn't give them enough nicotine in comparison to smoking to get off the cigarettes. It is most always better to start higher and then lower it when and if you feel you need a less strong level. The alternative is to give up and go back to smoking.