When photographing your model who is your friend, they might be a little bit shy and sometimes feel awkward when posing for you. To be able to overcome their fear, be sure to communicate to them. Try doing it yourself first before telling them to pose that way, this way they know how to do it and they wouldn’t feel awkward.
When I have a photo shoot with friend, they ask me what to do and what kind of poses should they do. I keep telling them to be creative and just keep moving your hands, arms, feet, hips, head, eyes every time I click the shutter. I may intervene them just to get a great pose.
Be sure that you have a communication, if you see a pose that you like that they did, tell them to say ‘hold,’ or something.