She shot to global fame at the tender age of 16, with her doe eyes, slender frame and long legs.
Her enormous, heavily-lined eyes and drawn-on lower lashes made her the poster girl for youthful Sixties beauty - so it's safe to say that Twiggy knows a thing or two about makeup application.
The star, 67, has now shared her top makeup application tips for women who want to exude youth without looking like they've tried too hard with FEMAIL - and every lady should take note.
Twiggy, who had to get to grips with her beauty regime from a young age after being scouted at 16, told FEMAIL: "Don't go heavy on the foundation and opt for a brown eye shadow as it's softer. I love a slick of mascara, a light blush on cheeks and natural lipstick.
"Always keep your foundation light and make sure you blend it well."
So what's the secret behind her youthful look? "I eat healthily and make sure I get at least eight hours sleep a night," she said of her simple age-defying regime.
The model also admits that she's had to tailor her diet as the years have passed, explaining: "When I was young and super skinny I'd eat everything and anything. I'm more conscious of what I eat now but I'm not fanatical about it, I love to cook and buy organic or free range meats and vegetables as I believe you are what you eat.
"I don't really diet but I try to eat sensibly with smallish portions. Then I have chocolate as a treat," said the star of her simple health and beauty regime.
Twiggy, who is married to actor Leigh Lawson, takes a relaxed approach to ageing and seems at peace with her advancing years.
Discussing her views on cosmetic surgery, she said: "I think it's up to the individual if that's what makes you feel good. However, I would always say to make sure you do your research thoroughly.
"Botox and fillers are not for me."
And fifty years on from finding fame, iconic supermodel Twiggy's career is stronger than ever.
At 67, the glamorous model, who is already a fashion designer for M&S, has been snapped up to curate a beauty range for the high street retailer, too.
Speaking about the collection, which comprises eight scented bath, body, fragrance and lifestyle gifts, Twiggy told FEMAIL: "I have been designing my fashion collection for M&S for four wonderful years and I was immensely thrilled when they asked me to develop a beauty gift range for them.
"All women deserve a bit of pampering and I wanted to create beautiful products with wonderful scents that everyone would enjoy using."
To promote the new range, which has arrived just in time for Christmas, Twiggy displays her age-defying good looks in a sultry set of campaign shots.