Poor old spare room. It spends most of the year as an understudy to other 'headlining' living areas, and never seems to get the chance to take centre stage - waiting in the wings, hankering to be filled with something more exciting than household junk.

[Read more: 9 ways to prepare your home for Christmas house guests]

But hark! The holiday season is (almost) in full swing; sleigh bells are ringing, invitations have been extended to family and friends and, it's likely to be a full house on Christmas Day.

Finally, the spare room has its moment to shine! But before the curtains are up and it's show time, why not give it a spruce up?

A few little touches might be all it takes...

Sleep like a yule log

"Transforming a chaotic spare room into a cosy guest bedroom may seem like a daunting task, but with a few simple changes, it's easy to create a homely space where guests can relax and unwind," says Kate Tansley, creative director at Multiyork.

"Space-saving and versatile, a sofa bed is a great way to accommodate family and friends in any size of home, and will allow a space to function not just as a guest bedroom, but as a home office or snug too.

"With a huge variety of styles, sizes and customisable options available, it's also easier than ever to find one that matches your decor scheme," says Tansley.

And when it comes to finishing touches, a well-made bed with a cosy throw and an array of festive scatter cushions, will create a comfy and inviting look that will instantly make the in-laws feel welcome.

Add a few simple necessities, such as guest towels, and some festive treats - maybe a wreath above the bed, a pine-scented candle and some mince pies (along with a tawny port) on a pretty plate, and guests will feel super-pampered.

Alternatively, an inflatable guest bed (with the latest comfort-enhancing technology) will gift your guests a great nights' sleep; especially if you invest in a plump, thick duvet with a high tog count, so you don't have to worry about having the central heating blasting all night long.

There's plenty of winter wonderland-themed bed linen and accessories, or Nordic-style designs - ideal for Christmas - around right now.

[Read more: When should I buy a Christmas tree? Our guide to buying a real one]

Naughty or nice

Children star at Christmas, and there's nothing more adorable than watching them unwrap their presents and hearing their squeals of delight. But all this excitement can be exhausting, and building a special space to keep them entertained will be a lifesaver for busy mums and dads (and grandmas and grandpas).

"Creating a festive-themed room suitable for children is easy with our cute and cuddly winter animal favourites, adorned on warming brushed cotton bedding to stay snug and cosy," says Katie Glenn, interiors expert at Julian Charles. "Layer with soft faux mohair and fur throws and cushions for extra comfort, and add the perfect finishing touches with Christmas themed accessories."

Nothing says Christmas like twinkling fairy lights - an easy way to create a magical atmosphere kids will love. Once they've opened their stockings, why not fill them with torn wrapping paper, and arrange them next to their favourite cuddly toys?

That way, they have their own festive play area to snuggle up in for a snooze, or show off their new presents.

[Read more: How to care for a Christmas poinsettia - and make it last beyond the festive season]

Spirit of Christmas

The run-up to the big day's been hectic, you've had an early start - and treasure that moment when you can finally sit down with a nice glass of red by the fire... There's no reason why the spare room can't be transformed into a cleverly curated 'cocktail bar' and snug room for grown-ups.

A cosy armchair, mini fir tree, fairy lights around the window frames, plus a sumptuous throw, some scented candles and a cocktail cabinet, will add ambience and a festive feel that's best bar none (and beats retreating to the loo for some peace and quiet!).

And if you suddenly have to accommodate a surprise guest after Happy Hour or the Queen's Speech, a bed that folds out of a box can double up as a pouffe with a tray of champagne flutes, before it's turned into a blissful bed where they can turn in for the night.