Gym, legs
A squat holding one weight at your chest, which helps you stay upright.
Phone at hip height, about 3 metres away, filming you from the side.
Your whole body, head to feet, needs to be in the picture. The coach will remind you if it can't see you.
Too shallow
Sit lower, elbows reaching towards your knees.
Leaning forward
Keep the weight tight to your chest and stay upright.