1.) THE BASICS OF BODY LANGUAGE
These are necessities I believe every subject should know when taking pictures and just to reinforce them, I have them here:
Don't slouch; stand up straight. Relax your shoulders and your face. Tilt your chin up but not too much. These are key to evoking a confident posture and people will gravitate towards that. Try your best not to go into default poses such as 'the broken arm' pose (In which one arm is folded across your chest, holding onto the other's elbow), or the 'sorority pose (hand on hip + over-exaggerated head tilt), or the 'princess' pose (leg tucked behind the other in a curtsy-like manner).
These poses are the most common because they are comfortable but they also show that you are insecure or unconfident. Really think about how your body conveys messages to others in your pictures! Try opening your body up. By keeping your arms to yourself too much, it doesn't exude as much confidence.
I know this may sound narcissistic to the first and last 's' in that word, but you need to know how you look. We all have a general idea of what we look like from other's perspectives and reflections, but do we really understand it?
Take selfies. Take as many as you can, every day, even.
Memorize the contours of your face. What angle makes your face look round and what angle can we see your jawline at best? Develop muscle memory for this.
Practice makes perfect. I didn't get comfortable in front of a camera until I understood at what position I needed to tilt my chin and explored from there on.
3.) LEARN FROM YOUR MISTAKES
I personally hated watching myself dance growing up and even now, although I hate it a little less. You are your worst critic. That's only because you feel the most vulnerable when you look at yourself.
I've learned that you have to analyze what you're doing, learn from your errors and you have to understand what you could be doing differently that would be more effective and more powerful.
Look at your pictures. Look at your selfies. Then try looking at other muses. Look at how other bloggers pose. I usually study a lot of poses from Tumblr since I follow a bunch of high-end blogs. I love couture and I love abstract concepts. I encourage you to practice them too! Practice poses that are difficult and practice poses that you usually wouldn't be doing, even if it doesn't fit your aesthetic. Challenging yourself and pushing yourself out of your comfort zone will make posing so much easier. Not only that, but it will add to your repetoire.
As a dancer, it's easier since that's all I do but I wasn't able to pick it up that quickly since dance consists of one movement to the next as opposed to isolating the moment from a period of time.
4.) DON'T THINK ABOUT IT
Don't put much thought into your poses. Move as freely as you want to. The more you think about how your photographer thinks you look, or the more you think about your face, or the more you force yourself to pose in an abstract way that is uncomfortable to you, you will get stiff.
There is no right or wrong way to posing.
Modeling is an outlet. You need to feel good to look good and that energy will convey a positive and strong message. This is where the muscle memory helps most. Ignore all other thoughts and the world around you (especially if you're shooting outside and people are looking at you) and focus on the intimacy of you and the camera.
That in itself is a sacred moment and therefore nothing else should get in the way of that.
5.) ADDITIONAL TOOLS
If it helps, try playing music of an artist you live through vicariously or music that makes you feel like you can conquer anything.
I personally play Beyonce when I can. She is fierce, fearless and plays as different characters so easily and so when I shoot, I pretend that I am her. When that happens, I am instantly washed over by this empowering feeling and my most abstract poses come from that.
I think that's one of the things that sets my style apart from other bloggers: it's that I'm conceptual in my pictures and deconstruct traditional blogging of standing in front of walls by turning it into something completely dimensional.
If it helps, use your clothing as tools to make your poses more intriguing. Hands in pockets, wearing jackets over shoulders, holding onto purses, placing a hand on your hat. Bring the viewer's attention to these objects.
Surroundings are great for this too. Whether it's a chair, the floor or simply putting a hand on a wall can be the best start to poses that are more striking.
When it comes down to it, you have yourself at the end of the day so learn not to depend on other objects as a crutch for your posing. Be aware of each body part. Fold your arms across your chest, run a hand through your hair, or put a finger under your chin.
The world is your oyster.