Lisa Hunrichs, multiple time world champion teaches us how to perform a Figure Four set.
In Freestyle Frisbee a set is when the Frisbee is under control and then set up into the air to lead into another trick. A Figure Four position is when an arm goes under the inside of the same side leg. I.E. the right arm goes under the inside right leg or the left are goes under the inside of the left leg. The arm and leg together cross a little like a 4.
A Figure Four set can be done either from a rim delay or a flat nail delay but the body mechanics change slightly for each. A Figure Four set is a great visually and leads well into other tricks.