Beware of the Blink! . Some models get into a habit of anticipating the strobes and start to close their eyes when the picture is about to be snapped If you have to blink, try to blink between exposures. This is not always easy, especially if you are working in a photography studio.
Get into the habit of not paying attention to the flash and concentrate wholy on the pose, your body language, hand position, etc. and your images will come out as you expect.