yah there is such a thing as too much tweak...... i was tweaking the shit out of my mutes one day to see how far i could go and well.... my ski popped off in the air, I was about at 200degrees when my ski popped off in the air. I pulled the rest of my 360 with my ski in my hand :O I landed one ski after i threw my ski out of my hand( when I landed) I washed out....... There is such a thing as too much tweak! now for streaching tips..... nothing better than tweaking the trick ur about to try in the chairlift!!!
1.ur streaching the exact muscles u need to streach
2. you get to know how far you can go without it hurting
3. you get to practice and visualise the grab
hope my tip helped