You could book an appointment with a personal shopper at one of the big department stores. It's usually free and you don't have to buy what they suggest if you don't like it.

While you are in the store have a look at the beauty counters. I've recently had my make up done by a make up artist on the Clarins counter at John Lewis (apparently they send make up artists round the country to help out at the counters and boost sales), and I often find the Benefit girls helpful. Again, it might help if you make an appointment. Check them out until you find one that's willing to do it for free, or who will charge but refund the charge if you buy something. Good luck. Sella.