The singer has since recorded two albums, appeared on stage in the West End and even unveiled her own clothing collection. Impressive, right?!
Reveal caught up with Diana to discuss her must-have beauty products, how she feels when she looks back on The X Factor and feeling star-struck by Kings of Leon...
You're fronting the Wrigley's Extra White Bubblemint National Smile Month campaign - what made you want to get involved?
"When I was younger I wasn't very confident with my smile, and I was really bad with my dental hygiene. My mum took me to the dentist and they gave me those plaque sweets which go bright pink with every bit of plaque, and I looked in the mirror and my whole mouth was pink! It was mortifying. So I'm happy doing this campaign and encouraging people to chew their gum, get their confidence back and smile!"
What are your favourite beauty products?
"I love Laura Mercier Tinted Moisturiser, £33.50, and Laura Mercier Secret Camouflage Concealer, £26.50. I'm also obsessed with the Laura Mercier body butters, flavours like vanilla, pistachio and almond. Also The Body Shop Cocoa Butter Lipcare Stick, £4, for my lips. I use the Cargo Contour Palette, £22, it's really handy, and Chanel Bronze Universal, £32, which is a creamy base. Then I like Burberry lipsticks and I have a MAC eyeshadow quad with different shades of brown. I also love my leopard print Tweezerman tweezers and my Sisley mascara."
Any bargain beauty buys?
"Rimmel Natural Bronzer, £5.99, is really good, and also Rimmel Soft Khol Kajal Eye Pencil, £2.99. Rimmel do a good liquid liner too, and I really like Barry M Nail Paints, £2.99 each."
Do you like to do your own make-up for an event, or do you prefer someone else to do it for you?
"I have a really good relationship with my make-up artist Brendan, I've worked with him for years. He's going to move to LA though and it's killing me inside! I love him doing my make-up, it's such a treat, but on a normal day-to-day basis I'll do my own. I'd love to have someone do it every day though, that would be great!"
How long does it take you to do your own make-up?
"I'm actually quite quick, so probably around 20 minutes. Although if I'm going out then I like to have that getting ready process - have a glass of wine, do my make-up… then have to start it all again because I've had too many glasses of wine and I look orange or my eyeliner has gone everywhere!"
Are you quite good at doing your own winged liner?
"I'm really bad! I never know what's going to happen, sometimes I do it and it's amazing in one try, then at other times I spend about an hour. Then I get eyeliner in my eye and get a weepy eye!"
What beauty products do you always carry in your bag on the red carpet?
"I always have my lippy, which is usually by Laura Mercier on Burberry. I'll carry my Wrigley's gum because you don't want smelly breath on the red carpet! I tend to carry a MAC powder because I can get a shiny forehead and nose, and that looks bad in photographs. I've got quite a big forehead so I need to powder it down!"
Who is the best celeb you've met?
"I was obsessed, and still am, with Caleb from Kings of Leon. I was going to an awards party and was in a bit of a bad mood, I didn't know if I wanted to go. I was feeling a bit down that day, I think I felt insecure about the dress I was wearing. Then I got there and had a great time, and all of a sudden the whole of Kings of Leon came in and Caleb was there. I was plucking up the courage all night to go and speak to him. I remember Dermot O'Leary was like, "Vickers, it's your one chance, you've got to go over!" So I went over and had a massive full-blown conversation with him. [It was] the best thing of my life!"
What do you think when you look back at your fashion and beauty looks on The X Factor?
"I think they were quite good, seeing as I was only 17 and stepping into the world of fashion. I was really young, I'm nearly 23 now and sometimes look back at hideous outfits I've worn or make-up looks. But that's a part of growing up, I went on the telly at 17 and usually, at that point, you're going through a bit of a bad phase in life, and I had to do it publicly. There are some photos on the internet I don't like."
How do you achieve your beachy, wavy hair?
"I sort of just sleep on it! I use a hair oil by Wella to tame my hair so I'm not like a crazy Tarzan woman. For the red carpet Brendan uses curling tongs and puts a few extra waves, but he barely touches it really."
Is your make-up collection at home massive?
"It was, but my boyfriend George made me do a clear-out. He bought me this gorgeous little vanity table. It's really beautiful but there was so much make-up on it that I didn't even use. George was like, "Get a bin bag, get it out!" But I still have a secret stash of beauty products underneath my bed which he doesn't know about!"
Diana Vickers is the face of Wrigley's Extra White Bubblemint campaign for National Smile Month 2014, encouraging people to chew sugarfree gum for a clean and healthy smile. Check out the Wrigley Extra UK Facebook page to find out more: www.facebook.com/extraofficialUK.
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