First, when I'm teaching students how to point their feet, I try to emphasize the word FEET. It is not just about pointing your toes - it begins much higher, in your ankle. You should begin pointing your feet by pushing the ball of your foot downward, or away from you. After elongating your foot, then you point your toes. Here are some pictures that should help explain.
Step one: push the ball of your foot away from you.