Mind those booby traps

Forget breast surgery. All you need is a proper cup size.

Here's a wonderful tip for those considering breast augmentation. I can help you, as I have helped so many women, to go up several cup sizes without having to spend either money or time in hospital wrapped in Tubigrip bandages. Get properly measured for a bra.

Almost all women (and I feel safe making this very sweeping statement) wear the wrong size bra. Seventy per cent is the statistic put out by lingerie specialists, but in reality it's far higher. Most women wear a back size too big and a cup size too small. So those wearing a 36B are actually more like a 34C or D. See? Instant aggrandisement. The common misconception is that your breasts should be shoved together in your bra. But unless you're after a plunge look, your breasts should never get that friendly. The centre of the bra, often adorned by a pretty ribbon or jewel of highest value, should touch your breast bone. The back of the bra should be below the shoulder blades; anything higher, and the back size is too big. The breasts should not be trying to escape out of the front, nor to the side under your armpits. Spillages mean the cup size is too small.

I thought I knew lots about bras and am rather sniffy about being measured. So when, two years ago, I ventured into the incredibly glamorous lingerie department of Selfridges, I thought I knew it all and that no one could possibly tell me anything I didn't already know.

But I'd been in breastfeeding bras for the previous two years and felt a bit lost, so said "yes" when this woman asked if I needed help. Once I'd got over the shock of finding out I was now a 34FF (I had ventured at a 34E), Dianne the Wonderful proceeded to comb the shop floor for bras in my size. There were none of the matronly offerings that get passed through the changing-room curtains at Rigby & Peller. Dianne suggested pretty, supportive bras as well as functional ones that were still pretty stylish. Then she showed me how to wear my bras. I mean really wear them. Number one: lean forward to put your bra on. Number two: once done up, arrange your breasts in your bra by scooping them up so that the underneath of your bra sits unhindered by flesh. Number three: once on, clasp your bosoms through the bra and hoick them up, then get someone to adjust the straps accordingly; most of us wear the straps too long. I spent £120 on bras that made me look really fantastic. I won't buy a bra now unless Dianne is there to help me.

In my experience - which is pretty extensive, let it be told - the girls in M&S can't measure for toffee, so whatever you've been told your your bra size is there, ignore it. John Lewis's bra fitters are pretty good, though.

Disclaimer: there's more to life than having big breasts.

Annalisa Barbieri was in fashion PR for five years before going to the Observer to be fashion assistant. She has worked for the Evening Standard and the Times and was one of the fashion editors on the Independent on Sunday for five years, where she wrote the Dear Annie column. She was fishing correspondent of the Independent from 1997-2004.