If you have a dream to be a model you need to be able to show a range of emotions and looks for certain shoots. Practice in the mirror or in front of friends differing emotions, looks and body positions.
Happiness, sadness, anger, smugness, angst, contemplation, smile, frown, wince, bemused, astonished, deflated, fed up, melancholy, arrogance, ignorance
Standing tall, squat, lying down, sitting, standing over, standing under, bent over, leaning back, leaning forward, side on, front on, back on
Practice all to the extreme, yell into the mirror to see what look you get. Actually cry to see what it looks like. See how long you can hold a squat for and can you make your self look taller than you are.
If you are able to provide many looks, positions and emotions your photographer will love you for it!