Sophia McDermott shares with you a wonderful drill that strengthens the core and incorporates the butterfly hooks, so that you can use your butterfly hooks to take your opponent's weight off you. Butterfly hooks are one of the best tools to use for escaping and to sweep with, but also to deal with your opponent's weight so that you don't get squashed and flattened to the mat. Give this drill a try
https://www.sophiamcdermott.com/BJJ-with-Sophia