Have her look away from you. Instead of staring straight into your lens have the subject look at something else. This could be something in the shot; for instance have her look into a vanity mirror, or take one of a man and the newspaper he is reading. Sometimes it's even more intriguing is to have your subject looking at something that isn't in the photograph -- think of a boy gazing into the distance in thought.
Take your shot when she isn't expecting it. While she is taking a break from those poses to freshen her lip gloss, snap a few frames. Unplanned moments often turn out to be the ones that truly show the subject's personality.
Think of a baby's feet nestled in her mother's hands or the curve of her one lovely hip, or her nose against the petals of a rose Another good photo can come out of the knees and feet of a soccer player right before the winning goal.
See what happens when you do not focus on your subject. Instead of bringing the child blowing bubbles into focus and blurring the background -- do the opposite. How interesting to have the child slightly out of focus with that one perfect bubble in razor-fine detail. Or the couple walking on the beach; have them slightly out of focus and bring the seagull into clear view.
Change the expression is important. Instead of posing your subject, experiment with posing her face. Tell her to think of her most embarrassing moment ever or her first kiss. Ask the little boy which is the silliest animal ever. You will be amazed at how much a single thought can change the entire feel of your work.