Your bra is almost certainly too big, you’re probably putting it on wrong – and you should wear a red one under a white T-shirt

Many women go wrong with the band size – probably 85%-90% of us are wearing a bigger bra than we should. Around 80% of support comes from that back band, and if it is too loose, the shoulder straps over-compensate, so they dig in, or there’s not enough support in general. The band should feel firm, not tight – you should be able to fit two fingers comfortably around the elastic all the way round. Start on the loosest set of hooks and eyes because as the bra stretches naturally with wash and wear, you can tighten it.

In an underwired bra, the wires must not sit on the breast tissue, but right underneath, and the bridge should be flat against the sternum. Next, there should be a bust in each cup – nothing falling out, cutting in, or no gaping in the cup. The straps should feel comfortable on your shoulders – not falling off, or taking too much pressure.

If you’re getting help from a fitter, ideally they will gauge size by eye, not with a tape measure. Tape measures aren’t elasticated, unlike bras; and anyway, you can be a different size in different brands – a 34D in one brand, but a 38D in another.

As far as colour goes, think about the rest of your clothes. For caucasian women, red works under white T-shirts (yes, I know it sounds odd), but if you’re a woman of colour, a bra close to your skin tone is the best option; white or cream tends to show through.

If you’re supple enough, put your arms in first and fasten the bra at the back, because it should be firm enough that it’s difficult to twist it around your body. Also, if you’re stretching and pulling it round every morning, it won’t last as long as it should. If you have three bras on rotation, each should last nine to 12 months.

Josie Fellows, lingerie styling specialist at Rigby & Peller, was talking to Emine Saner