I spin control stick, Tap Cstick different directions (you have to tap it one direction at a time and reset it to neutral, you cannot circle around with it fast like on the control stick), Mash all L/R/Z, and depending on how bad I want to get out, I will sometimes use other fingers to hit A and B.
Kosmos probably does the same thing as me, same for other people who get out fast. I think the biggest difference is when you start. For example, usually when I get out super fast, I KNOW before I get grabbed, that I have been grabbed, and start mashing/moving RIGHT then. A lot of other people I know get grabbed, realize they have been grabbed, and then start after a bit of delay. For the people that break out faster, they usually are mashing right when they get grabbed/even beforehand.