Great video from Rafa Mendes on how he approaches guard passing. It’s all in Portuguese, but somebody in the comments has translated the essence of what he’s saying:

“He’s advocating not gripping in order to stop your opponent gripping.

Constant movement from side to side and turning knees inward to assist with trapping and lateral movement.

He uses a knee-forward stance in order to make gripping his feet difficult.

This is all in the context of starting a pass and getting into a good initial position where you have control and your opponent doesn’t.

He likes using ankle/feet, knees, shins along with open palms to push and trap legs to stop guard recovery as well.

Also, don’t try to pass if the guy is on his side looking at you, you need to get him looking away to pass.”