Stand behind the person hitting the ball not to the side.
But, I know beginners who focus more on power than technique as well. They should just work on hitting it straight first then work on the mechanics to get them the distance. A shorter drive into the fairway will help lower the score rather than a long drive into the rough/woods requiring a pitch out recovery shot. I have a natural slice and if I try to overpower it, off it goes into the rough but if I power down I can keep it straight and the angle actually keep my 2nd shot closer to the hole.
I remember once many years ago (maybe 15 years) when my 3-some got paired up with a beginner. I can’t remember the course but it was a tricky one and difficult that day with the wind conditions. We’re not great golfers ourselves with our best guy shooting low 90s (although he can shoot mid/low 80s) and the other two of us (me included) were shooting 100-105 that day. This guy we got paired up with was using some friends clubs and ended up shooting somewhere around 140. At the end of the round he stated he loved the game so much that he wanted to go out and spend over $2,000 on his own set of clubs (that is $2k in 15 years ago dollars). We’re told him, to save his money, buy a pair for under $1,000, and spend the other $1,000 on lessons to learn how to hit it straight first.