OK, Some of this comes from http://www.wikihow.com/Walk-Like-Alice-Cullen
This, has helped me, and i hope it helps you.
1. Dance Lessons- they help you get more comfortable with your feet.
2. Cullens walk faster than humans. And since, Alice has more energy than anyone else, she walks faster. plus, add a little leap into your walk.
3. DONT stick your leg out!! you'll look stupid! like before, add a little leap.
4. DONT attempt this in heels, clunky or stilettos, or you'll do a Bella.
5. Put one foot in front of another.
6. Dont breathe, so heavy while walking. Take alot of little breaths. Remember: the Cullens dont NEED to breathe as much as humans do, it's just a force of habit, and a sense of smell.
7. As Bella, mentions in New Moon, the Cullens "get distracted alot", so when you walk fix your gaze on many differet objects. Balance, this out. Every _#_ steps look at _#_ different objects.