Simon Duffy was in Whole Foods in New York when he realised that men were underserved by the skincare industry.

"I went to Whole Foods to get a particular moisturiser for my girlfriend. It was a really cold wintery day in New York and so I thought, 'I'm going get some moisturiser too,' but there was just nothing there for men," he told Business Insider.

In 2005, he decided to launch his own skincare brand — Bulldog — with men in mind. It's now available in 26 countries around the world, and controls around 20% of the market share in the UK.

While his background was in business rather than dermatology, as a consumer himself, Duffy has since learned plenty about men's skincare routines — and has plenty of insights into the mistakes many men continue to make.

According to Bulldog's website, most men still aren't moisturising daily — but that's the least of their issues.

Scroll down to see the skincare mistakes you may be guilty of, and what you should be doing instead, according to Duffy.

You don't cleanse and moisturise.

You don't cleanse and moisturise.
You don't cleanse and moisturise.
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You don't change your razor blades often enough.

You don't change your razor blades often enough.
You don't change your razor blades often enough.
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"Men are shaving less but when they do shave I think men are tempted to stretch out how long they take between changing their razor blades," Duffy says.

He adds that nobody should be shaving with a cheap razor: "If you are going to shave, make sure you're using proper equipment."

You don't wash your beard.

You don't wash your beard.
You don't wash your beard.
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If you do grow out your beard, it's important to keep it clean and well-maintained.

"Beard's just get so dirty," Duffy says. "If you think about how much you're running your fingers through your beard throughout the day, anything you get on your fingers is going in your beard."

In 2015, a swab analysis conducted by ABC-affiliated station KOAT found that some beards had levels of bacteria" comparable to toilets."

To tackle this, Duffy advises using a proper beard shampoo whenever you wash the rest of your hair.

You don't style your beard.

You don't style your beard.
You don't style your beard.
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Washing your beard is a great start, but if you really want to double down on your facial hair, it's important to style as well as clean your beard.

"You can tame an unruly beard if you need to be smart for the office with a balm or an oil," Duffy says.

With so much attention paid to styling the top of our heads, why not the bottom too?

Duffy advises beard-growers to buy a razor with a precision trimmer, "

You wash your face with shower gel.

Consider taking a shorter shower.
Consider taking a shorter shower.
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This is one of the biggest mistakes guys can make in their skincare routines, according to Duffy — and that's because of a key ingredient.

"Naturally-formulated shower gels are dodging an ingredient called SLS (sodium lauryl sulphate) — that is a really cheap foaming agent," he says.

However, he adds that it's found in a lot of more common shower gels.

"This foam is often mistaken for a feeling of actually cleaning you but... it's actually more for the experience than the efficacy of cleaning," he says.

Instead, Duffy recommends buying a proper cleanser that's designed for your face.

You use toothpaste on your spots.

You use toothpaste on your spots.
You use toothpaste on your spots.
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There's really no excuse to be using toothpaste on your breakouts anymore.

"Use a proper blemish targeter," Duffy says. "You're really looking for AHAs (Alpha Hydroxy Acids) or witch hazel, which would be a great natural ingredient for spots."