when some of my tops grow to fast, or basically they reach to the light, with other small plants in the room and i dont want to raise the light i bend back the tops and tie down with a bread tie. I believe the method is called scrog. Check out this post and see how i did them. https://steemit.com/cannabis/@jonyoudyer/veg-room-update-5
Just remember when you bend the branches that you make sure they just got watered because they will snap very easy if they are dry.