Wear knickers. You’ll be surprised how many don’t.
Sports cars look the part, but they’re a nightmare to get out of. Similarly, avoid going down the civilian route and taking a black cab, as it’s a long drop from car to kerb and anyone can get their camera up your skirt. I recommend a classic BMW or Merc. Leather seats are a good platform to slide off elegantly.
Always keep your knees and ankles together. Until you start walking, of course.
Don’t drink on the way there. I know someone who fell flat on their face in front of ten photographers outside The Groucho. Horrific. Her career has never recovered (at least it’s left more space for mine).
Always have someone to open the door for you.
Practice, practise, practise!