The fastest way to make your skin look better is by cleansing properly

If you’re currently relying on wipes or just water, try using a balm or oil and then a warm flannel to remove makeup – skip this in the morning – followed by a gentle face wash or cleansing milk to clean your skin. It will usually give you smoother skin in a week.

If a product is en route to the plughole, spend less on it

Everyone wants to know where to splurge and where to scrimp, and my advice is always this: spend the least on things that are quickly washed away (cleanser, body and face wash), saving the extra cash for the products that sit on your skin all day, like serum and foundation.

A good SPF is one you want to use

I was once shouted at by an extremely defensive brand founder for saying this, but I stand firm: I don’t care how innovative and groundbreaking a sunscreen is, if it is greasy, ashy, smelly, bobbly, gritty, streaky or drying, it’s no good to anyone. What makes one worth buying over the other is your keenness to use it. And that hangs on having an appealing, user-friendly formula that works for you. The recommended dosage for facial sunscreen is roughly two full finger lengths of product for face and neck combined. In my experience, people will apply half of that at most. So use as high an SPF as you can, err on the side of lavish and get as much additional protection from SPF makeup as you can.

No one is looking at your pores

Social media, magnifying mirrors and widespread photographic retouching have convinced at least three generations of women that their pores are gaping chasms that must be filled or closed. Wherever I go, women tell me theirs are enormous. But no one – and I mean no one – will have noticed. At best, people see us and think “she looks nice”. More often, they pay no attention at all.

Botox does not replace skincare, just as a mattress does not replace sheets

Toxin injections – for those who choose to have them – work on muscles and are fantastic on dynamic (mobile) wrinkles, frown lines and mild drooping. But they do nothing for the condition of the skin itself. For the over-30s, a glowy, healthy-looking complexion comes either from a considered lifestyle and solid, diligent topical skincare routine, or a genetic lottery win, never from Botox. Moreover, if any topical skincare product claims to be “Botox in a bottle”, it isn’t. The two are not remotely interchangeable.

Gorgeous makeup is 75% skin prep

Flaky foundation and concealer is not a makeup problem, it’s a skincare problem. When people tell me their makeup clumps and cakes, I usually discover that they’re not exfoliating regularly. Using a flannel to cleanse (see above) and deploying a gentle exfoliant a few times a week will give a smoother surface for anything that comes after.

Retinoids work

It is perfectly possible to have fantastic-looking skin without retinol and it is certainly not an ingredient that suits everyone. But if you’re looking to tackle signs of ageing, like slackening, lines and discolouration, retinoids (vitamin A derivatives) like retinal, retinol and tretinoin, work. Unlike many other heavily marketed ingredients, the benefits of retinoids are not a matter of opinion or debate. That said …

People are doing too much

A few years ago, I noticed that the vast majority of women I met at in-store beauty events were using far too many high-concentration products and suffering from irritation and a visibly compromised skin barrier as a result. Just because an ingredient such as glycolic acid or retinol is proven, it doesn’t mean that using them all together at maximum strength will yield greater results. Quite the opposite, in many cases. A little glycolic acid gives glow, too much glycolic leaves skin even duller than before, for instance. An actives-based routine is all well and good, but know that inflammation is one of the leading causes of premature skin ageing, so don’t ever confuse broken, angry and painful skin with effectiveness.

No one waits long enough

As a society, we are impatient. Usually, when someone tells me an active ingredient like retinol, vitamin C or peptides hasn’t done anything for them, I soon discover they used them for a week or two before moving on to something else. Skincare ingredients can take time – around six to eight weeks – to yield results. If you’re purely an instant gratification person, try humectants such as hyaluronic acid and glycerin, which give a temporarily plumped up, juicier looking appearance, and facial oils, which impart glow.

Wipes don’t cleanse skin any more than Febreze washes clothes

They are an emergency measure for when you might struggle to get to a basin, say during festivals and hospital stays. Don’t bother buying expensive ones. Simple is as good as any wipe gets.

The secret to skincare is actually doing it

The boring truth is that good skin comes largely from diligent care rather than products themselves. There is absolutely no point in buying expensive moisturiser, if you then sleep in your makeup at night. My skincare routine is fast but consistent: light cleanse, serum, moisture and sun protection by day; deep cleanse, retinoid and moisturiser by night. As with diet and exercise, it’s what happens most of the time that matters. So repeat daily, the occasional boozy late night excepted. But that reminds me …

“Someone’s beautiful nan always used water and Vaseline and died with not a line on her face”

It makes for a charming story, and I admire her genes and modest lifestyle. But what people think it disproves about the science around sun damage, smoking, pollution, inflammation and stress, I don’t know. There is wisdom in a light touch, certainly, but moderation is entirely compatible with sophisticated products containing more complex ingredients than paraffin.

If you are told to buy a whole product range, it doesn’t work well enough

“Cross-selling” skincare is an old-fashioned sales tactic and a bad sign. If a sales associate tells you need several same-brand items in order for a regime to bear fruit, then none of the products is good enough individually. Walk away.

A good daily intake of water helps massively in making skin look its best

So do I drink enough of it? No. I am a husk.

Women who preach about letting skin age gracefully are almost always physically attractive and under 35

It’s a perfectly reasonable ambition, but please come back to me when you’re 45 and tell me you still think life is this simple (and that you don’t miss your old lips).

“Clean beauty” is an American marketers’ invention

In fact, it’s born from the fact that the US has looser safety standards for ingredients than Britain and the EU, which are among the strictest in the world. If you take a principled environmental stance against petrol-derivatives, animal ingredients and the like, modern “clean” brands can be most welcome. But know that “chemical-free” is an utter nonsense, and take opportunistic American scare tactics around deadly and dangerous “toxins” in skincare with a pinch of salt.

Acne is not an inevitable part of being a teenager

It is medical condition that can have a serious impact on someone’s mental health. No one should expect a young person to just put up with a health problem that causes them physical discomfort and emotional distress. If acne is negatively impacting your child’s life, take them to the doctor and ask for proper treatment, just as you would with an injured limb or persistent headaches. Treatment will usually involve a prescription for topical peroxide-based products, antibiotics or, in serious cases, a strong form of retinoid (or an escalation through all three until effective). And while acne is common in adolescence, it is also prevalent among adults, particularly around menopause for women. Don’t seek to fix a health problem with beauty products. Get a prescription.

“Wall Street high-flyer/trust fund rich kid got eczema/psoriasis and couldn’t find a single product for her skin …

Then visited a quaint village somewhere far away where everyone ate a rare fruit/rice/plant and looked 12, was inspired to launch her own $2m skincare brand and would now like to share her journey” is not the unique, credible and newsworthy story founders and marketers believe it to be

I have heard a version of this at least twice a year for the past two decades.

If you don’t have much money, consider spending it on brands with stacks of it

Mega brands owned by L’Oréal (such as CeraVe, Garnier), Unilever (Dove), P&G (Olay), Beiersdorf (Nivea, Eucerin) and Walgreens Boots Alliance (No7) have enormous bulk-buying power, recruit top cosmetic scientists and spend more annually on research and development than most brands spend in a lifetime. To squeeze all of this into an affordable price point is hellish for a small, independent brand. So if you have necessarily shallow pockets, you may want to put your principles aside and plunder the deeper ones of a global bigwig.

Dermatologists will disagree

My respect for dermatologists is infinite. I couldn’t do my job without the knowledge and expertise of those trained in the science of skin health and disease. But as with experts in any field, opinions frequently conflict. For instance, I once worked with a senior male derm who doesn’t wear sun protection unless abroad, while many of his peers would be appalled. I know several who disagree wildly on acne treatments. Nonetheless, dermatologists seem to be the only type of doctors whose word the internet believes to be beyond question or second opinion. Meanwhile …

Any good dermatologist will tell you that no one knows more about the temperament and responsiveness of skin than the person who lives inside it

You are the expert in your own skin, so pay attention to how it responds to ingredients and lifestyle changes, how it behaves in different weather, which treatments work. The best experts – whether lay or medical – combine their learned expertise with lived experience.