Those pots and vials always interested me most, for the florid promises they made and, as I learned more and more about how they worked, for what they can really do for you if you know how to choose what works and leave out what doesn’t.

I've just published a book, Great Skin: secrets the beauty industry doesn’t tell you (Gibson Square, £12.99) that distils the brilliant stuff I was taught by the world’s biggest skincare brains, so you can understand once and for all how to make your skin the best it can possibly be. Here, I highlight some of the most essential (sk)insights I think everyone should take to heart. They will give you skin you will be proud of – guaranteed.

Without cleanser and SPF, your other skincare is worthless

A sulphate-free, mild facial cleanser (whether oil-based or water-soluble) twice a day is essential: skincare won’t penetrate dirty skin and no, skin does NOT self-cleanse. UV rays are skin’s greatest ager and dehydrator, blasting out of the water all the good you’re trying to do for your skin with anti-ageing ingredients and even moisturisers. So a broad-spectrum UVA/UVB sunscreen with an SPF of 30 or higher is the must-have topper of your skincare sandwich.

Skincare is like brushing your teeth

It’s all about consistency: the best skins are the ones that have received gentle, protective care and hydration (and SPF) from their teens onwards. It’s never too late to start loving and respecting your skin, so begin now and you’ll find yourself reaching for resurfacing acids, anti-ageing ingredients and treatments years later than everyone else.

Acid one-upmanship is bad for your skin

An eye-catching percentage of an exfoliating acid (“10% glycolic!”) is not a great thing. Firstly, acids are formulated alongside neutralising agents, whose level determines how strong your product truly is. It means that the ‘10%’ you paid so dearly for might actually not be very potent! That’s not a bad thing for your skin, but it may not be what you bargained for. Secondly, over-use of acids will lead to skin problems down the line, so don’t make the strength of your acid your priority. Base your choice instead on the reputation of your brand, your skin’s needs, and on the balance of acids and other ingredients. A blend of acids is preferable, as all of them perform in a slightly different way, and additional calming and hydrating ingredients are a big plus.

A lot of skincare is better than it admits to be

Officially, skincare may only hydrate skin’s surface and temporarily (as in, for a matter of hours) improve its looks. Anything more than that and it must be classed as a drug. But in truth, many great cosmetics can improve skin function long-term and visibly transform it, a fact that is regularly downplayed because if not, it would mean losing out on the lucrative skincare business...

Think light if it doesn’t feel tight

You don’t need a heavy moisturiser, but you don’t need NO moisturiser, either. Every skin needs water-based hydration and humectants (substances that draw water into the skin). This might be enough if your skin is oily: a hyaluronic acid or glycerin-based serum or gel could be all you need. Add light lipids such as squalene or jojoba oil in a moisturising lotion or cream if your skin is normal, and occlusive, moisture sealing butters such as shea butter in a richer cream if you have dry skin or dry patches. Basically, choose the moisturiser that keeps your skin feeling comfortable and supple all day.

Serums are a better investment than face masks

If masking makes you love caring for your skin, keep going. There’s nothing wrong with a great mask. But what you apply is basically a large amount of serum or cream, when a few drops or small dabs of these potions are formulated to work no less well. Masks are said to ‘force ingredients deeper into the skin’, but in truth, the product’s delivery system is responsible for that. So in terms of cost per use, a serum is the better choice!

You don’t need an eye cream or a night cream

If you avoid mineral oil, fragrance, alcohol, and other irritants in your face creams and serums, and use the lightest formulations that still keep your skin hydrated all day, you can safely use any face product around your eyes (except perhaps the richest face butters, which could leave you with puffy eyes). Highly active ingredients such as retinol or AHA’s can be too much for this area, though, so they should indeed only be delivered in a special eye formulation. While I’m at it, there aren’t many reasons to for a separate night cream either. Obviously, SPF creams are only for daytime, while most retinoids (forms of vitamin A, of which retinol is the most famous) and leave-on AHAs are meant exclusively for nighttime use as both make skin more sun-sensitive. Beyond that, all the ingredients that regenerate skin are just as helpful during the day as they are at night.

Celebrity recommendations are… tricky

That’s because so matter how fantastic your favourite influencer looks, her (or his) skin is not like yours. We all have unique skins and unique needs, so recommendations can be great, but only if you can be sure the person it’s coming from has the same skin type, concerns and circumstances. And that is rather hard to determine. So check every recommendation for what it’s meant to achieve, what ingredients are in it, and against what you know your skin requires. A little bit of research leads to a LOT of great skin!

Price is not a good guide for quality

It wasn’t always the way, but great skincare is now available at any price – truly. Some top-line tips that do help you truffle out a great product:

If your product makes a big play of certain ingredients, such as vitamin c, niacinamide and algae extracts, make sure you see them in the first half (preferably the first quarter) of the ingredients list on the back. It’s this list that doesn’t lie, while the label on the front sometimes does! Keep in mind, though, that ingredients such as retinol and many antioxidants work at minute levels so will be low on the list.

If the list is dominated by mostly silicone, mineral oil, alcohol and glycols, it’s won’t do much except moisturise.

Latin words refer to botanical extracts and plant oils – a good indication your product is nourishing at the very least.

Instead of gorgeous packaging, invest in its functionality: opaque, airless, hermetically seal-able, i.e. directed at keeping active products fresh.

Botox does nothing for your skin quality

If your skin looks rough, dull or patchy, it will remain so if you don’t look after it with skincare and a healthy lifestyle. Caning it and thinking you can ‘fix’ your skin with botox is the wrong idea: it will do nothing for skin’s translucency, clarity, texture, evenness in tone, or lack of congestion. As for age prevention: if you have any significant lines that bother you, botulinum toxin will get rid of them in a matter of days if and when they appear at a later age. There is absolutely no need to ‘prevent’ them by freezing your face in time – fact.