There's really only one way to learn how to turn like that... leaves your brakes in the truck.
I have a local xc loop with lots of rolling ups and downs and bermed corners. Often when i ride it...i wrap my brake finger around the bars and try ride it with no brakes...I havent made it the whole way without cheating...but its super scary fun. Have to look for anything that will catch a tire or add traction in a corner. Fun way to change up an average trail.