What is a "double full full full"? Well, for one thing, it is not simply achieved. It is a triple backflip with four body twists.
As the skier goes up the ramp, they stand as straight as they can on the skis while their arms are extended above their head. When they reach the end of the ramp, the push off slightly to start their twisting. Then the skier rotates their hips like when playing with a hula hoop. By bending the back and rotating the hip to one side, they then do a side bend to achieve the full power for the rest of the first twist. At the end of that step, the skier is upside down in the middle of their first backbend and full twist. If the left arm is lowered, the more they are tilted to the right. And the more they tilt, the more they twist.
In the first full flip, the skier must complete two full twists to get the double full full full correctly. The arms must be tight against the sides after the first backflip to twist faster. At the end of the last twist and finish of the third backflip, the skier raises their arms above their head again to slow themselves and land easier.
Athletes of all kinds don't learn by reading how to do it, they watch and practice. Giving an explanation of what a move is, isn't the same as seeing it because you can't always picture exactly how things are just by reading about it. I am quite sure my explanation has not helped give an idea of what the double full full full looks like. I recommend watching this video. “Double Full Full Full”. It helps to see what it is supposed to look like and gives scientific terms to help describe if that's what you're into. But anyways:
