Keep your feet next to each other, firmly on the ground. Don't shift around. Avoid swivel chairs. If no other chair is available, don't swivel because the movement will distract viewers from your message. Men cross their legs at the knee.
Women cross their legs at the ankles with knees together.
If the reporter stands, you stand. If the reporter sits, you can sit or stand. Try to stay on the same level as the camera so it neither towers over you nor looks up at you.