The six beauty rules you should break: ROSIE GREEN debunks the conventional wisdom on everything from leaving make-up on overnight to drinking two litres of water a day

Even though I’ve tested 167,542 products, I still love beauty. I’m as intoxicated by serums, perfume, lipsticks and liner as I was when I first interned at Elle in 1993.

I love how scents can make you feel powerful, comforted, or sexy. How sharing a great budget purchase is like giving someone a tenner: a feel-good moment for both of you. Or even how the cleansing ritual can be soothing in difficult times.

But there are things I don’t like about the industry. How it plays on insecurities, causing you to buy products you don’t need – always emphasizing the ‘you have to get this’ narrative.

When I started (then thin eyebrows and even thinner models were coming in), that was the way ads and glossy magazines got you in the door.

‘Your skin is dull because you don’t drink the equivalent of a reservoir every day, follow a 12-step skincare routine or smother it with unicorn tears every night. You have to spend time and money to achieve perfection.”

Now I’m in the unique position of being able to try anything, so I can tell you that some beauty rules have no credibility, or don’t apply to all of us.

My biggest takeaway from over two – oh crikey, make that three – decades in beauty is that we are all individuals, so what works for you may not work for me. And vice versa.

So don’t feel inadequate if you don’t adhere to the beauty dictate created by a marketing team. This is my approach – but you do too.

1. Skip the moisturizer

I remember going cold turkey for the first time, on the advice of a dermatologist – it felt like going outside without panties: indecent and exposing. While my skin was missing its comforting blanket of unctuous cream, I stopped using moisturizer because it aggravated my rosacea-prone skin (with rosacea, the skin feels dry, but is just inflamed and acne-like). Was my skin drier/dull without it? No. It was recalibrated. Many cosmetic doctors I interviewed agree that active ingredients are best served in a serum, and that a moisturizer may be unnecessary or optional. A good SPF is often sufficient. When my skin needs a drink, I use a hyaluronic acid serum (current favourite: Teoxane Advanced Filler, £84, teoxaneshop.co.uk) or get moisturizing injections.

2. Skip facials

In my work I am offered facial treatments every day. I don’t have them because my sensitive skin often looks worse rather than better afterwards. Now, not all facialists are created equal, and there are some great therapists who can tailor a treatment to your skin type and who have an arsenal of toys (like LED lights, professional peels and derma rollers) that will help you make a difference. But the facials offered by big-name brands usually adhere to a standard protocol of scrubbing, steaming, multiple cleansing, and masks that can aggravate problem skin. That said, I do miss their de-puffing, circulation-boosting and relaxing elements, so I think facials can provide a solution for many.

3. Don’t double cleanse

The skin is not like dishes: it should not squeak. We are taught that super clean is the way to prevent blemishes and aging, but the opposite is true. Overdoing the washing and scrubbing compromises the skin’s barrier, which is essential for keeping skin healthy and aging optimally. My skin is happiest with lukewarm water and a simple wash-off cleanser (try Avène Tolérance Extremely Gentle Cleanser, £14.49, superdrug.com). However, I will indulge in a separate eye make-up remover (Lancôme Bi-Facil, from £15, lancome.co.uk).

4. Stretch hairstyles longer than six weeks

The perceived wisdom of regular trimming doesn’t work for me because instead of having a short, low-maintenance haircut, I have long layers that can wait. But now that I’ve gotten grayer and my hair color is lighter, I realize that it’s my color that necessitates more regular salon visits. Now it’s the six-week toning sessions that give me the biggest bang for my buck. Phillipa Lock from John Frieda’s Aldford Street salon in Mayfair explains: ‘It’s a treatment that revives faded colour, counteracts unwanted brassiness and can be cheap.’

5. Leave my makeup on overnight (sometimes).

Of course it is good to wash it – and the day’s waste – off. It allows nighttime skin care to penetrate and reduces pore clogging. But a few mistakes won’t destroy your skin. I’ve seen models with perfect skin tones who are skincare slaves and others who are scrupulous and suffer from persistent breakouts.

A lot of it has to do with genes, so there’s no point in shaming people with imperfections. And – honestly – when I have my makeup done by a professional, I often remove everything except the eye makeup. As Liz Hurley says, it looks better the next day.

6. Drink two liters of water a day? Not me

Being well hydrated is a good thing. It promotes digestion, circulation and recovery after illness. But one skin care expert told me you’d be dead before any signs of dehydration showed up on your face. Dermatologist Dr Stefanie Williams adds: ‘It’s a myth that drinking lots of water will fix dry skin. The problem is that you lose too much through evaporation, so it’s like trying to pour water into a bucket with a hole. Fix the leak first!’ Keep your skin barrier intact by treating it well and using a ceramide product if necessary (try Dr Jart+ Ceramidin Cream, £15, cultbeauty.co.uk).

Therapy in a bottle

Luxury – In the toughest of times, I used the Ilapothecary Beat the Blues Pulse Point roller (£29) daily. The new Eau de Parfum version is a more refined option.

Fewer –M&S Apothecary Tranquil Body Wash’s cypress and thyme scent (and its good looks) belie its price tag.

£110, ilapothecary.com (left) and £7.50, marksandspencer.com (right)

Sweet treat

Nudestix Tinted Hydra-Peptide Lip Butter Collection – in the colors Dolce Nude, Candy Kiss and Super Plum – plumps and polishes the lips, adds a subtle color shine and tastes delicious.