Adjust the seat height so that when your seated with your chest against the padding, your shoulders are aligned with the rotation axis of the machine. Grip the handles and ensure that your forearms are against the padding.
Start by raising up from the elbows until they are aligned with your shoulders, then slowly lower back down to just before where the weights rest. Ensure that your forearms stay in constant contact with the padding. Conduct the movement in a slow and controlled manner. Repeat for the desired repetitions then gently rest the weights down.
Avoid relying on your wrists to raise the weights or using excessive momentum.