1. A long white dress

Probably the most important rule in the book. No-one wants to be the girl wearing a white maxi dress to a wedding, unless you're the bride, of course. It's not hard, so don't be selfish about this.

Sleeve, Shoulder, Textile, Standing, Formal wear, Style, Pattern, Fashion, Neck, Waist, pinterest

Left: £1,875, Alexander Wang. Right: £110, Y.A.S. Studio

Small side note: it's always wise to carry a little shoulder-coverer such as a stole or a modern blazer, if the wedding is likely to be super formal or in a church. You can whip it off later.

2. White/ivory/cream anything

These days, bridal fashion is so fresh and exciting you may turn up to find the bride wearing a similar white skirt/jumpsuit or even mini dress to you. Prints are fine, but anything in a block bridal colour is a real no-no.

Clothing, Sleeve, Shoulder, Textile, Dress, Photograph, Pattern, Joint, Standing, Formal wear, pinterest

Left: £65, Little Mistress. Right: £70, Chi Chi.

3. Anything see-through

So while the sheer dress trend might be enjoying some popularity, it's not right for a wedding. While Bella Hadid and the whole Dior gang might look staggeringly good with their boxer-briefs on show under a sheer tulle skirt, you'd really be upstaging the bride to appear at her wedding with your knickers out.

That's not to say a little bit of sheer isn't okay. Sheer panels around the upper chest and the legs are okay, so long as you're not revealing anything that wouldn't be considered kosher at a formal event.

Clothing, Dress, Pink, Fashion, Gown, Neck, Sleeve, Formal wear, Beige, Day dress, pinterest

Left: £50, PrettyLittleThing . Right: £55, ASOS.

4. Anything super low-cut

Again, while the super-duper plunge might work at an evening event, where things tend to get a little racier, it's not wedding appropriate and certainly not if you'll be anywhere near a church.

Clothing, Dress, Black, Shoulder, Cocktail dress, Sleeve, Neck, Little black dress, Fashion, Formal wear, pinterest

Left: £22, Club L. Right: £22, Club L.

5. Flip flops

Flip flops are just not wedding attire. Neither are jelly sandals, birkenstocks or trainers. They're all too casual. If you're baring your foot flesh and you're not keen on high heels, think grecian or kitten heeled sandal.

Footwear, Brown, Skin, Shoe, Photograph, Joint, Tan, Beauty, Sandal, Foot, pinterest

Left: £24, Gandy's . Right: £25, Glamorous.

6. Jeans

Jeans, besides joggers and pyjama bottoms, are about the most casual of trousers available. So unless your bride has informed you that you'll be mucking in on a farm for her wedding, you'll need to lay off the denim. Smart trousers, if you're not keen on a skirt, are absolutely fine. There are plenty of great formal jumpsuits out there. But how about a palazzo pant with a nice blouse? Drama, volume and the three-quarter versions make room for some really stand-out footwear.

Clothing, Green, Jeans, Dress, Pattern, Leggings, Sleeve, Pattern, Neck, Design, pinterest

Left: Seven For All Mankind. Right: £698, Merchant Archive.

7. Denim of any kind, really

Denim is pretty much on a blanket ban from weddings. Try something in a chiffon or silk instead.

Clothing, Sleeve, Shoulder, Textile, Standing, Joint, Pattern, Red, Dress, Formal wear, pinterest

Left: £12, Vero Moda. Right: £408, MGSM.

8. A tiara

You are not the bride. You are not participating in some sort of strange pageant. There is little excuse for any woman bar Kate Middleton to be wearing a tiara. They're terribly gauche. But if anyone had any right at all to wear one it would be the woman getting married (though ket's hope she chooses something a little more chic, shall we?).

Hairstyle, Forehead, Hair accessory, Style, Fashion accessory, Headgear, Organ, Beauty, Fashion, Youth, pinterest

Left: £12.50, ASOS. Right: £215, Gucci.

9. Anything too garish

You can probably work it out for yourselves but this means: animal prints, neon colours, bells and whistles. As much as we actually adore the below Dolce & Gabbana pineapple dress, it's just a little too Carmen Miranda for a wedding. You risk drawing all eyes to you rather than the bridal party, which isn't a very nice thing to do. Prints are fine, in a more muted way, and with less of the ruffles and neon.

Clothing, Dress, Green, Day dress, Fashion model, Yellow, Pattern, Pattern, Neck, Fashion, pinterest

Left: £690, Dolce & Gabbana. Right: £16.50, Shein.

10. All over black

Black used to be an absolute faux pas at weddings - you're not at a funeral, after all. The occasion shouldn't be sombre. But a little black trim on an otherwise differently coloured dress is fine. Just be sure to jazz up your accessories with some sparkle and/or colour, to make it clear you're in a mood for revelry rather than sad contemplation!

Clothing, Dress, Fashion, Sleeve, Day dress, Fashion model, Pattern, Footwear, Shoulder, Little black dress, pinterest

Left: £795, Temperley London. Right: £300, Self-Portrait.

11. Slogan T-shirts

This isn't 1999 and no one cares that you have Girl Power, or that you like the Rolling Stones, or are monied enough to afford a designer name.

Clothing, White, Black, T-shirt, Jeans, Shoulder, Fashion, Sleeve, Footwear, Trousers, pinterest

Left: £490, Givenchy. Right: £215, Asilio.

12. Clubbing shoes

There's a difference between shoes for a night out with your girls in a glitzy or dark club, versus the sort of shoe you pair with a classy dress at a wedding. A statement shoe is absolutely fine and we love a metallic shade or even a bit of hardware, but you don't want to look like you're dressed for a night venue rather than a day venue and you definitely want to be able to dance the night away without breaking your ankle.

Footwear, High heels, Sandal, Shoe, Slingback, Font, Fashion accessory, Brand, Basic pump, pinterest

Left: £795, Gucci. Right: £260, Michael Kors.

From: Cosmopolitan UK