Well, this should boost the M&S share price: our lovely friend Mary Greenwell has joined, as Beauty Ambassador - and we couldn't be more pleased to share a series of her 'Masterclasses', beginning with how to create the Flawless Foundation look. (One of the most-Googled beauty challenges of all...) Here's the step-by-step, with Mary's wisdom. (To find any of the products she mentions, meanwhile, click on the list at the foot of the page).

1. To create flawless finish, great skin is key. First start by massaging a primer onto the skin; primer forms a great base to hydrate, cover imperfections and also to help ensure that your foundation has the staying power to last the day. I used the Pur Hydrate and Balance Primer and applied over the whole of the face.

2. Your foundation should be chosen depending on the finished look that you require. I used the Autograph Illuminating Touch Radiance Foundation and applied it to the skin, taking extra care to work well into the side of the nose and jaw, to achieve a flawless finish.

3. The under eye area is one of the first areas to show signs of tiredness! Apply concealer gently under the eyes; this will lift the area to remove any signs of imperfection.

4. A flawless finish is not complete without a healthy glow, dot Pur Blusher in Apricot on the apple of the cheek and slightly up above the cheekbone to create a natural flushed look.

5. To widen the eye apply the Autograph Twist-up Cheeks Highlighter in Pearl underneath the brow arch; you can also apply this highlighter to the top of the cheekbones to add a slight shimmer to accentuate them. (A PS from Beauty Bible: probably not if you're over 35...!)

6. This look is mainly about the skin - so the eyes just need minimal make up. Apply one coat of Diego Dalla Palma Cigilione Mascara in Brown to both the top and bottom lashes, taking care to use minimal mascara to create a really natural effect.

7. To finish the eyes take a brow pencil and gently fill in the brows. Apply using light short strokes where required with the Autograph High Definition Brow Pencil.

8. The lips are the last step to creating this look. Outline the mouths natural shape with the Diego Dalla Palma Lip Pencil, then fill the lips with the Autograph Ultra Shine Twist-up Lip Colour in Nude.

And those products (click on any name to find on-line at marksandspencer.com)

• Pur Correcting Primer Hydrate and Balance/£22.50

• Autograph Illuminating Touch Radiance Foundation/£12.00

• Pur Blush in Apricot/£19.50

• Autograph Twist-up Cheek Highlighter in Pearl/£9.50

• Diego Dalla Palma Cigilione Mascara in Brown/£17.00

• Autograph High Definition Eyebrow Pencil/£6.50

• Diego Dalla Palma Lip Pencil/£14.50

• Autograph Ultra Shine Twist-up Lip Colour in Nude/£9.50