I think it's a little different in America for an event like the Academy Awards because their red carpets start mid-afternoon because of broadcast times, so they have to start getting ready a little earlier.
If I had my dream red carpet preparation it would go something like the following (and not at all like the reality, which is often me hopping down a hotel corridor putting a shoe on with one hand while I Blackberry an email with the other hand and my management team shout pertinent briefing notes for the night's event at me).
Two months out: To prepare for an event like the Academy Awards I'd have a stylist working months in advance. They'd probably be approached by designers and we'd have a shortlist of dresses on a rail ready for the big night. I'd definitely want to keep my options open right up until the last minute though because I wouldn't want to walk down the red carpet in front of the eyes of the world feeling like I'd worn the 'wrong' dress when I was under 360-degree scrutiny.
I'd decide on the hair and make up person I wanted to use well in advance too. Maybe I'd have done a magazine shoot and got on with someone well and decided I'd love to have them in my hotel when I was getting ready, making me feel great before I went out there. You always want to have people around you who give you a buzz so you're feeling up and fabulous when you step out of the car and into the spotlight.
Four weeks out: I don't know for sure that it's true, but according to the magazines, A-listers do at least a month's personal training ahead of an event like the Oscars. I can tell you I've never done that in my life but perhaps it's different in the acting world because they're either on a film or they're not, so when they're not they've got time to do that kind of preparation.
Two days out: I'd want to do my fake tan a night, or ideally two nights, before the event so that it's not freshly done. Then if there's any minor disaster it's less obvious and it's easier to blend it with some makeup.
On the day: I'd allow two hours for hair and makeup. It would probably only take an hour and a half but I'd need half an hour to stop, grab something to eat so I didn't pass out halfway down the carpet and reveal my Spanx to the world's entertainment media (always Tabs' major worry)!
First I'd have my hair set to give it body, then I'd have my makeup done, then the stylist would go back and style my hair after it had a chance to cool off. Once it's cool the volume is set and my red carpet hair tip is that you can always make something flatter, but you can't create volume at the last minute!
The finishing touches: I'd probably give myself half an hour to get into my outfit, put on shoes and accessories and grab my handbag before gliding seamlessly (I wish) to the pre-booked car to be whisked off to the whirring cameras and flashing lights of the red carpet. As the saying goes..."Eyes and teeth...eyes and teeth!!!"