For the latest in this series, Mary Greenwell - M&S's newly-appointed Make-up Ambassador - offers her expert advice on create a Classic Red Lip. (It's a beauty conundrum generating over 5,450* ‘How-to’ google searches per month...) Mary’s Top Tip: 'The first step to creating the perfect classic red lip is to ensure you use a good lip liner. It is very important to line the mouth when using red as you need to have control of where the colour sits. Lip liner also helps you to correct any unevenness in the lip area.'

1. Take your lip liner right into the corners of the mouth and outline your perfect red lip, taking care to press softly as not to change the natural shape of the mouth. I used the Autograph High Definition Lip Liner in Red. When you are happy check that the liner is even on both sides of the mouth before moving on to step 2.

2. To create the perfect bow, use a pale contour pencil to highlight the cupids bow and the top of the upper lip line, this creates the illusion of fuller lips. For this look I used the Studio 10 Age Reverse Perfecting Lip Liner.

3. As lips have been lined there is no chance of going over the lines, so apply your perfect red straight from the bullet to the lip (there is no need to use a brush). I used Pixi Mattelustre Lipstick in Raspberry Blush to create this look. Starting with the bottom lip, press down firmly with the bullet to really build up the colour. Then rub your lips together and apply lipstick to the upper lip using the same application technique as before.

4. To finish the look, take a Q-tip and use light strokes on the outer lip line to create a softer, prettier finish. Voilà - there you have the perfect red lip.

Products used...

• Pixi Mattelustre Lipstick in Raspberry Blush/£14.00

• Autograph High Definition Lip Liner in Red/£6.00

• Studio 10 Age Reverse Perfecting Lip Liner/£22.00

*Google UK data from July 2014 - July 2015 on behalf of Marks and Spencer Beauty