No home should be without a really comfortable sofa; the sort that you can sink into with a novel and a box of chocolates on a wintry day, and on which you can fit the whole family to watch the World Cup.

But choosing one isn’t easy, and how it looks in the shop doesn’t always tell you how it will look in your home, where proportion and its relationship to everything else in the room will be key. There’s no substitute for careful measurement-taking. Length and width are important, but so too are height and depth: sofas that are too deep are often uncomfortable for short people.

Then there’s your lifestyle to consider: does the sofa have to withstand pets, children and rumbustious family life?

So where to start? Many shops now offer sofas, from Ikea, where an Ektorp three-seater is just £255, through Habitat, where a Tahoe three-seater costs £799, to the Conran Shop, where the Burnham is £2,583. And that’s without mentioning specialists such as Sofa Workshop, which offers excellent value and serious advice, and Laura Ashley, which specialises in undramatic, classic shapes at reasonable prices.

Looks matter, but so do the insides. The frame should be sturdy, preferably made of hard wood from sustainable sources. The frame should be screwed and glued – as Marks & Spencer, for example, assures us all its frames are. The support should be good, with proper springs and not cheap wire coils. Finally, there’s the upholstery. Good foam provides long-term support, but one of the best options is an inner core of foam with an outer wrapping of feathers to soften.

Start by finding a look that suits you and inquire about its construction later. The Ikea solution – something cheap, clean and usable – could be right for those who still have a few years of family life ahead of them, after which they can upgrade.

Finally, the outer surface matters, too. Patterned is obviously less inclined to show the dirt than plain, leather is tough and benefits from some wear, but if you fall in love with something creamy, it’s best to keep it covered with a series of throws until your children are tucked up in bed.

Aesthetically, tastes seem to run to low cushions that can be put together in a modular fashion, of which Roche-Bobois’ Mikado 2 collection (www.roche-bobois.com ) is probably the prime example. The pieces can be bought singly and thus gradually (from £585 for a small ottoman) and come in an unusually vibrant, Kenzo-like colour palette. Long, low, sleek designs are a speciality of the Italians (check out B&B Italia at www.bebitalia.it ), but the most beautiful sofa I’ve ever encountered is the Lota, designed by the great Eileen Gray in 1924 (from £3,470 at www.aram.co.uk ). It has four huge feather-filled cushions and there are two lacquered box units at either end. There are lots of different colour combinations and fabrics, but the Manilla cotton, used on the original, is the nicest.

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