Actress Blake Lively. (Picture: Reuters)

'The Shallows' star is known for her flawless complexion and enviable glow and now her beauty guru, celebrity makeup expert Kristofer Buckle, has opened up on Blake's approach to her routine.

Speaking to Refinery29, Kristofer said: "My formula for Blake's makeup is pretty simple. We both look at makeup as paint - it's all about the colour and the texture - and she's not sensitive about what I put on her face. It could be $2 or $100.

Makeup artist Kristofer Buckle with Blake Lively. (Picture: Instagram)

"I mean, sometimes we will go more bold, but that's an easy look that we know will work. Blake's gorgeous, and doesn't need a lot of makeup. It's not just her face that's stunning, Blake just really radiates beauty in a visceral way - she's sunshine."

The A-List cosmetics genius - who owns a QVC has a cosmetics line that sold out just 45 minutes after launching - has worked with the likes of Jennifer Lopez, 49, Cindy Crawford, 52, and the entire Kardashian clan, however, his journey with Blake, 31, has given him a lot of professional satisfaction.

Kristofer added: "When Blake was new in the business, she was so excited about the exploration of makeup. She wanted all the bells and whistles - lashes, contour, an overdrawn lip - so we look back and laugh at those early 'Gossip Girl' posters, because she looked very done. Now, her whole look is a lot softer - except, obviously if we're working on an event like the Met Gala."

Blake Lively attends The Met Gala 2018. (Picture: Reuters)

Kristofer has revealed that Blake - who is married to 'Deadpool' actor Ryan Reynolds - now likes to sport a natural look and he has spilled his top tip to achieve that with eye makeup.

He said: "In the past, we've done that by piling on lots of black mascara. Now, we want to take the same approach to emphasise her eyes, but we do it by contrasting the lashes with an iridescent shadow, because that's more modern. We will also use brown mascara as opposed to black, she just prefers a softer lash now. Those tiny, micro-adjustments keep the look current and evolving."