Trial and error and that's it. I wish the best to you learning a good skid stop, your life may depend on it. =] My friend is so good at stopping it's like he has breaks or something but he is crazy mashing in SF like he owns the streets of downtown, I want to go riding right now, but I am faded haha. I am weak and I actually have a front break even though I have never used it JIC.
To all a great ride!