As children develop into teens, the overall influence a parent has on them becomes limited, whether the parent accepts it or not. They come in fourth behind friends, teachers, and, the Internet.
The best a parent can do is to create a positive relationship with a teen and hope that they have learnt enough to help them as they traverse their most formative years. To successfully do that, there are some basic habits that you have to imbibe in them. As the saying goes, “Habits are easy to form, but hard to break”. It is advisable to help them develop good habits that they will not forget.