When performing the Single Leg X Sweep it's all about proper foot placement and shifting the hips.
When setting up the Single Leg X Sweep you want to close the distance with your opponent and get underneath them. Once you are under them it becomes a much easier game of disrupting balance and setting control of the position.
Let's focus on controlling the Single Leg position prior to the transition. By controlling your opponent in this position using balance displacement they will open the door for the perfect transition.
Hitting the sweep from Single Leg X is all about the timing and framing of the knee.