Last-minute costume: 8 ideas you can pull together in 10 minutes

A fancy-dress party tonight and nothing ready? A good last-minute costume never relies on detail, but on two things: a silhouette you can identify from across the room and a single signature accessory. That's it. Your guests' brains recognise an overall shape before looking for an exact likeness, and that's precisely what makes improvising work. Here are eight ideas you can put together in ten minutes with what you already have, plus the traps that ruin an entire evening.

The ten-minute rule: silhouette plus accessory

Take any successful costume and you'll find the same structure. First a silhouette, meaning a piece of clothing that changes your overall shape: a full-length onesie, a sheet, an oversized jacket, a head-to-toe single colour. Then a signature accessory, one item that names the character: sunglasses, ears, a hat, a kitchen utensil put to new use.

The trap is starting with the idea. You decide you'll be Cleopatra, and spend forty minutes hunting for what's missing. The right method is the other way round: open the wardrobe, pull out the three most unusual pieces you own, and ask yourself what they suggest. A dressing gown suggests four characters; a hooded onesie suggests six.

Third rule, and the most overlooked: you must be able to sit down, drink, eat and go to the loo in it. A costume that rules out any of those four gets abandoned in the hallway before 10 pm.

Should you panic-buy a costume?

Short answer: no, unless you plan to wear it more than once. The party costumes sold in supermarkets are designed for single use, and it shows in what they're made of. The British charity Hubbub, with the Fairyland Trust, analysed several hundred Halloween costume lines sold in the UK: 83% of the material used was oil-based plastic, with around 7 million costumes thrown away every year after a single night.

The problem isn't only environmental, it's practical. These costumes are cut from very thin non-woven fabrics, with heat-sealed seams that give way at the first big movement. Plenty of people have lived the same scene: the cape tears on the doorstep, and the rest of the evening is spent in a T-shirt.

The sheer volume involved is dizzying on a French scale: around 3.3 billion items of clothing, household linen and footwear are put on the French market every year, according to Refashion, the French textile industry's eco-organisation. Adding a costume worn for three hours to that pile makes little sense when an ordinary wardrobe already holds everything you need.

The 8 ideas, stopwatch in hand

1. The hooded monster

The most effective of the lot, because the silhouette does all the work. A hooded one-piece onesie changes your overall shape instantly, and horns or big eyes on the hood are enough to name the character. No preparation, no make-up required.

Time: 1 minute. What you need: hooded Monster Pyjamas, or any roomy hooded onesie, plus slippers.

An added bonus, and a decisive one in November: it's the only costume on this list you'll actually be warm in, that lets you sit cross-legged, and that you'll happily keep on until 3 am. The next day, it goes back to being clothing.

2. The ghost, owning it

A white sheet, two holes cut with scissors, and you're done. The ultimate classic still works, as long as you don't apologise for how simple it is. The version that gets a laugh: add a pair of sunglasses over the sheet.

Time: 3 minutes. What you need: an old sheet, scissors, perhaps a belt to cinch the waist.

3. The black creature

Black from collar to socks. Two ears cut out of black card and fixed to a headband or a hair clip. A stroke of black pencil to extend the eyes, three pencilled whiskers. Cat, panther, demon: everyone will see what they want, and that's absolutely fine.

Time: 8 minutes. What you need: black clothes, card, an eyebrow pencil or eyeliner.

4. The tourist on holiday

Patterned shirt, shorts over knee-high socks, bum bag, cap, and sun cream left unrubbed on your nose. A camera or a phone slung across your body completes the picture. It's the most universally understood costume, and the most comfortable of all.

Time: 5 minutes. What you need: a loud shirt and a pile of everyday accessories.

5. The office zombie

White shirt, loosened tie knotted askew, jacket over one shoulder. Dark circles drawn in grey pencil and smudged with a finger, messy hair, a little watered-down lipstick at the corner of the mouth. The trick that makes it all believable: untuck the shirt on one side only.

Time: 7 minutes. What you need: your work outfit, a pencil, ten seconds of hair chaos.

6. The film character in a dressing gown

Bathrobe, sunglasses, glass in hand. Half the room recognises the character immediately, and the other half will just think you're very relaxed. Also works as a boxer, with a towel round your neck and makeshift gloves.

Time: 2 minutes. What you need: a dressing gown, one prop held in your hand.

7. The improvised duo

As a pair, people recognise you twice as fast. Salt and pepper, with a white T-shirt, a black T-shirt and two paper labels. Day and night. Wi-Fi and bug, with one sign saying "connected" and another saying "error 404". The concept does all the work; the clothes don't need to be sophisticated.

Time: 6 minutes. What you need: two bold colours and some paper.

8. The one proud accessory

Sometimes the best solution is not to dress up at all, but to wear a single out-of-place item with total seriousness. A cardboard crown all evening. A pair of swimming goggles. A hard hat. The contrast between a normal outfit and the object creates the comic effect, and nobody will accuse you of cheating.

Time: 30 seconds. What you need: nerve.

The minimal make-up that changes everything

Three moves are enough, and none of them needs theatrical kit.

First, hollowing: a grey or brown pencil under the eyes and on the temples, smudged with a finger, is enough to look exhausted or sinister. It's the basis of every undead character.

Next, contrast: a thick black line extending the corner of the eye outwards radically changes the expression of the face, even from ten metres away in a badly lit room.

Finally, texture: a little foundation or flour on the face kills the shine on your skin and gives that matt look that visually separates your face from the rest of the room. Best kept for parties where you're not planning to kiss many people.

The mistakes that ruin the evening

The "no pockets" row deserves an extra word, because it ruins more evenings than all the others put together. A costume without pockets turns your phone into something you have to watch constantly, and you'll end up putting it down somewhere. Check this before you leave, not when you arrive.

And if the party keeps going

The best sign of a successful last-minute costume is the moment you forget about it. If by midnight you've stopped thinking about what you're wearing, you've won. If you spend the evening adjusting a cape or holding up a drooping ear, the idea was a bad one, however good it looked.

That's why outfits that double as comfy clothes almost always beat technical costumes. They make it past the second hour, they survive the sofa, and they turn naturally into an after-party outfit. If the mood drifts into group pyjama mode, our guide to a grown-up pyjama party has a few ideas for carrying on through the night without getting changed.

Cover photo: David Garrick - Bangbola / Unsplash