Be confident. A supermodel strut depends completely on confidence. You have to have a brave, commandeering walk to look like a supermodel.
Push your shoulders back. This will add presence to your walk and elongate the neck.
Push your pelvis forward. This will make your stomach look more concave and make your strut look more purposeful.
Balance weight on the ball of the foot. This might be awkward because we usually balance weight on the heel. Keep the weight on the ball of your foot behind your toes, especially if you're wearing a tall, skinny heel.
Keep those legs up. You want to take as long a step as possible. Lift your knee high and push it to the ground--almost spider-like. It sounds like a weird march, but the result is pretty powerful.
Point the toes in. Try to walk in a straight line, bringing one foot in front of the other as you move.
Maintain a steady speed.
Keep your chin up. This ties in with the whole confidence thing and will keep your "audience" engaged.