The dreaded question i've heard on soooo many occasions when i was first starting out, before i knew how to guide my model.
"I don't, I absolutely do not want you to pose. I want you to move as naturally as possible and allow me to capture the essence of who you are."
This is and will forever be my answer, i will help guide you as you transition though out your femininity/masculinity in front of the camera. From a photographers position it sounds so easy to tell a model that.. WRONG!!!! We know that embracing your individuality within modeling is difficult when you are shown from several different outlets to look a certain way. What if I told you that how you think you have to pose is not exactly how YOU need to pose? Of course like any thing worth learning their are fundamentals that highlight best practices, there are literally foundation guidelines that help you but are not law. Understand that although they aren't law you must know the rules to bend or break them to suit your individual image.
Avoid the distractions!! I learned a few years back to pay attention to particular body poses that can be distracting. Biggest distraction I've always seen is the tendency to point the elbows towards the camera, I garuntee your elbows will be the focal point over your face. Think of your body as play doh and you can turn it into any shape you want, the only catch is it needs to be pleasing to the eye. Now before you retreat to your go to poses this is a perfect chance to experiment to see what is actually pleasing. Newer models spend the latter part of their sessions thinking more than actually doing, most times they are trying to remember that pose they saw in Elle, Vogue or Dazed and Confused.
Don't worry it's not that deep, depending on the mood of the shoot you will almost always nail it if you put yourself in the mindframe for that particular emotion. Let's use happiness as an example, if you are happy it shows on more than just your face it shows in your movements all through out your body. As photographers most times that's what we are asking you to translate is individual emotions that cant be replicated by anyone other than you. Pose your butt off and practice in the mirror, Always bring YOU to the shoot and not what you think we want you to be.
The dreaded can you change your face is something I know I am guilty of saying. Models I know you hate hearing this because it down right confuses you. So let's tell you what we mean, often times I get the "deer caught in headlights" face which is the face that most new models think is "the face", it's NOT. That expressionless face is the furthest from what we want from you, your have facial features and expressions for a reason use them. The most important statement I tell my clients is:
"don't be afraid to try anything that comes to you or feels natural, if it doesn't work we can just delete it."
All of my models tend to find a unique comfort in this statement, i tend to use "we" alot in our conversations because even if it's just you and I, we are a team. Practice is not just for home but also when test shooting is a great moment to "test" a new expression you've been practicing in the mirror. We will definitely tell you "yay or nay" while we are shooting with you. So all in all can you change your face is more of your chance to run through different emotions or facial expressions you've been working on or looking to try.
So in closing pose your butt off and practice in the mirror, always bring YOU to the shoot and not what you think we want you to be.