From not wearing white after Labor Day to avoiding double denim, there are certain fashion rules that were created decades ago and are still followed by millions of people even now.
However, according to experts, some of these style regulations are outdated, and those who still follow them may be unknowingly making their outfits look drab.
On the other hand, some of these old-school fashion rules might feel obsolete, but those in the know think they should still be adhered to.
Thankfully, the Daily Mail has broken down the fashion guidelines that you should eschew and the ones you should still stick to, as well as the style faux pas that are considered absolutely criminal to commit.
From stripes that could make you look like bigger to velvet that will have you sweating in the summer, these are the fashion rules to follow and the ones to break, according to experts.
Wearing white from Memorial Day to Labor Day
Taylor Swift stepped out in winter white this spring in New York City when she visited celebrity-beloved restaurant Via Carota, showing how it is done
Bella Hadid stepped out in Cannes in a revealing white dress with a plunging back to show how to style it for summer
Waiting until after Memorial Day to bust our your best white ensembles and then putting them away when Labor Day rolls around has long been a fashion rule.
But fashionistas often question the regulation, with many touting the benefits of wearing white all year long.
Taylor Swift seems to not care for the rule, especially as she steps into her bridal era, as she was seen wearing white on numerous occasions recently.
But according to experts, there are still plenty of reasons to keep the hue seasonal. Instead, Stylist and designer Iris Acevedo recommended wearing ivory or cream colors if you want to dress in something white.
Acevedo told the Daily Mail that ‘bright linen white in freezing weather can feel disconnected, while ivory cashmere, bone leather or antique cream tones feel intentional.’
Fashion expert Laura Unruh told the Daily Mail that ‘as someone who has been in fashion their entire life and continues to design classic styles,’ she feels it is best to follow this guideline ‘purely out of respect.’
While Unruh said it is technically acceptable to don winter white, she believes it is ‘a little disrespectful.’
The LOU.EARL founder explained that wearing white after Memorial Day harkens back to when people would ditch their dark colors of the cold seasons and swap them for white to show they were not working.
‘The white attire represented the American dream at the time, and the working class could take a break to have their leisurely summers which included the sand and the sea,’ Unruh said.
Avoiding horizontal stripes
Kate Middleton has mastered wearing horizontal stripes and often steps out in them when she is donning more casual looks. She’s pictured in 2019
One scientific study says that wearing vertical stripes, like Jordana Brewster above, is actually more unflattering than horizontal ones
Horizontal stripes have long been a tricky topic in fashion, with some people calling them classic and others labeling them as wildly unflattering.
Scientists have said that dark horizontal lines are actually more slimming than other clothing designs while another scientific study found that vertical stripes are even more unflattering.
The reality is that it is entirely dependent on the type of stripe and how the garment is made.
Acevedo said she believes there is a way to wear horizontal stripes as long as the tailoring and spacing is done correctly.
A classic navy and white striped Breton top is one example that celebrities like Kate Middleton and Alexa Chung love.
‘My mother always told me not to wear horizontal stripes because they can make you look wider,’ Unruh, who is based in California, explained.
‘While that may visually be true, I suppose it depends on which society or culture you’d like to dress and impress for, and how you’d like to express yourself.’
The expert said to try to avoid vertical stripes and to carefully choose your striped garments when you do decide to wear them.
Ditching velvet in warmer months
Zoe Saldana donned an orange velvet Alaïa gown in April in Santa Monica, testing the boundaries of when it is appropriate to wear the fabric
Gwyneth Paltrow showed off a velvet dress in December 2025 at the Marty Supreme premiere in New York City
Velvet is traditionally a cold weather fabric but in recent years people have been pushing the boundaries and wearing it even during the warmer months.
Instead of deep jewel tones, celebrities are opting for bold hues and pastels as a way to keep the fabric going all year.
Zoe Saldaña, for example, opted for an orange velvet Alaïa dress in California this April. But is it a fashion faux pas?
Unruh warned that if you opt to wear velvet in the spring or summer ‘you will sweat beyond any deodorant that you own’ because of the thick, tight and warm weave. Instead, she said it is best broken out for holiday parties.
‘You should also skip corduroy as that’s also a very heavy weave and wale,’ she advised.
She added that it is best to opt for lightweight linen and cotton once those warmer temperatures hit instead of looking dull and drab in heavy velvet.
Dodging double denim
Sports Illustrated swimsuit model Camille Kostek hit New York City in double denim in May
Beyonce perfected the double denim look while she was promoting Cowboy Carter and has leaned into it ever since
Wearing double denim has been controversial for years, although it briefly made a comeback with pop stars in the early aughts when Britney Spears and Justin Timberlake matched in their now-iconic double denim ensembles at the American Music Awards in 2001.
It returned yet again thanks to Beyonce during her cowboy core era, and she proved it is a solid trend as long as you do it right.
Acevedo explained that double denim can work with contrast, referencing Debbie Harry and Jane Birkin’s past successful double denim looks.
However, if you are not getting onstage or hitting a red carpet, double denim can make you look completely rural, Unruh warned.
‘It’s fantastic if you’re in Montana on a ranch with horses and cows,’ she quipped.
She added that it is best to ‘save the denim-on-denim for fall seasons or a fashion photo shoot while you’re in the barn.’
