What not to wear when it's hot (or cold)

Finally, a worthwhile reason to emulate Cher from Clueless, who takes Polaroids of every outfit before she leaves the house: the fashion networking app Cloth has now added sartorial weather advice to its roster of indispensable services.

What started as a social-media forum for people who enjoyed showing off what they were wearing has now evolved into something rather more practical. Simply array yourself in every outfit you own and snap each in turn. The Cloth app will then tag each look by the weather conditions it will suit, be that "rainy", '"warm" or more cryptically "work", essentially building a clothing catalogue that will tell you what to wear every day, regardless of gale forces or summer breezes.

Of course, you could do what I, a fashion-pro, do – look out the window. And if you still aren't sure, stick your head out too, to check for drizzle.