Adjust so knee is aligned with the pivot point of the machine and padding on lower calf.
Contract your hamstrings to the curl pad up and towards the back of your thighs as far as it feels comfortable.
Briefly hold at that point, then slowly extend back to the starting position in a controlled manner.
Fully locking out the leg on reps.
Foot angling too far in or outwards.
Upper body moving too much.
Place one foot onto the platform and adjust to allow the padding to be against the bottom of your calf.
Start by contracting your hamstring to the curl pad up and towards the back of your thigh, go as far as comfortable, then slowly extend back to the starting position in a controlled manner. Tense your core and use the hand grips to ensure your upper body remains stable. Repeat for the desired amount of repetitions, then switch sides.
Avoid rushing repetitions or limiting your range of motion.