How to start a new ball of yarn

I’m working on a scarf and need to start a new ball, everyone seems to have a different way to do this and I’m getting confused listening to all of them. Is there a video that I am missing…couldn’t find one. Let me know if you have a good explanation on how to start a new ball.

Thanks!
Eleanor

In the “Basic Techniques–more” section there are videos on different types of joins.