You don't know me, but I'm sure you'd recognize me if you saw me.

Imagine it's the weekly seminar, and you're scanning the audience from the podium. It's certainly a motley crew – about half men and half women, ranging in age from rabbit-eyed undergraduate interns to world-weary emeritus professors and every shade in between. I'm that late-twenties female post-doc about a third of the way back. No, not the fresh-faced newbie poised on the edge of her seat with lips parted breathlessly and pen already uncapped; not the one with crossed arms and jaded eyes who's clearly been in the game just a few years longer than she ever intended. And please – certainly not that woman with dishevelled hair, stained jeans and rumpled Gordon Conference T-shirt! I do have some fashion standards, you know.

That's me, just to her left. Call me X-Gal. I'm young but not green, enthusiastic but not nauseating – confident but not cocky. There's somebody like me in every lab: nearly ready to transit to the next stage, hoping to be a lab head but not necessarily blind to other possibilities if Plan A doesn't pan out. Loving what she does without being so starry-eyed about science that she's not fully aware of its warts.

Today I'm sitting in front of the Rampant Feminists – a notorious pair of middle-aged female lab heads who add a lovely dash of colour to the otherwise statistically average composition of our London cell biology department. I said that our department is half women, but if you plot us on a graph with increasing age on the x-axis and numbers on the y, with a white line for the girls and a black one for the guys, you see a dead even heat – until the thirties. Then something alarming happens: the black line begins to shoot upwards while the white line plummets faster than a PhD student's bank balance after payday. They even have a name for this, inspired by the shape of the phenomenon: the Scissors Diagram. Our department is no exception to the national or international average: the majority of our women are youthful, and all of the grey heads are male – except for the baldies, comb-overs and at least one suspected toupée, of course. (Poor dears. You do feel for them, don't you?)

I like sitting in front of The Rampant Feminists at seminars because they give a running commentary under their breath about everyone who enters the room:

RF1: My God, look at what she's wearing. Last time I checked, this was a cell biology department, not a brothel.

RF2: Well, just wait 'til the Christmas party: one drunken grope and she'll finally realize her supervisor is paying more attention to her cleavage than to her clathrin-coated pits.

But with these two, you can't really win. When the seminar speaker – a hotshot female professor with a Californian pedigree longer than your arm – is finally ushered into the room by the host, I hear RF2 mutter: Didn't Margaret Thatcher wear that same suit circa 1987? Yes, replies RF1, but with slightly smaller shoulder-pads.

From what I've gathered via eavesdropping, the RFs are obsessed with how woman scientists come across, and they're desperately anxious that we don't let the side down. Some might think their appearance-conscious attitude is shallow and missing the point, but I'm not so sure. In my experience, whereas male scientists can get away with pretty much anything – from Coke-bottle, Bill Gatesian boffin to the louche, unbuttoned George Clooney look – without their science being judged, we girls have to be extremely careful how we present ourselves. Something so superficial shouldn't matter – our talks and papers should speak for themselves – but unfortunately it does matter, so you'd be a fool not to at least think about it.

I admit that my attitude about this issue is coloured by a newspaper article my mum once sent me (when I was going through a rather awkward fashion phase involving pink highlights and ripped jeans) about how businesswomen should dress in the office. Studies have shown that flirting, make-up and provocative behaviour generally backfire, with the women in question being perceived as less intelligent – yet men also dislike it when women appear to act like `one of the guys'. If articles like these are correct, we're damned if we do and damned if we don't.

Although the article wasn't aimed at scientists, I reckon that the same is true in the lab. And it's important, because we need to get along with our male colleagues to get ahead, particularly in the sphere of informal networking, where a lot of the really important career-facilitative connections are made. Although the attrition of women in science is an incredibly complex issue, fuelled by multiple factors – and we can chat more about some of the other problems later – I think we tend to underestimate the importance of feeling like we belong in helping to keep us on track. Many of my female friends who've left science have done so out of a vague sense that they were on the outside, looking in, and they never really got the hang of all the seemingly superficial social tricks that women like the RFs have down pat. I'm certainly not suggesting that a sexy top will doom your eventual professorship, but if there are small things you can tweak to help your career progress, it's worth having a go.

So what's a girl to do?

I think the first thing to consider is that it is eminently possible to productively network without worrying about men at all. In our circle of related departments, the RFs and other female lab heads are always up for coffee with post-docs and students. Evening drinks are not always possible, what with child-care obligations, but it shouldn't matter what time of day you are getting to know your colleagues. These little social get-togethers are so punctuated by laughter and interesting gossip that what starts out as a little group of women in the common room often ends up a mixed group of colleagues, hanging on their every word. I don't know about you, but I've been to some of these mostly male pub sessions and frankly, they aren't any more fun. Only last night I was hanging out at the local watering hole in a mixed group, and two of the older male lab heads seemed more interested in comparing the size of their latest grants than truly listening to issues and concerns that their younger colleagues were trying to discuss. You could practically hear the clashing of antlers.

So how do you break into a conversation like this? If you want to get ahead in your field, you'll need to know how: you are inevitably going to want to talk to the top people, who statistically are more likely to be male. If studies are to be believed, you don't want to attract their attention with a low-cut blouse, but equally you will probably fail to charm by being aggressive, or pretending to be interested in the latest Premiership football scores.

What I do is just be myself, but with an extra layer of confidence (even when I don't entirely feel it). And you mustn't forget that when the time is right, a little bit of humour can go a long way. Another thing that's really key is not to be daunted when you get interrupted – because, honey, they will sometimes try to talk over you, and they aren't going to notice if you withdraw into a hurt silence. Just speak a little louder, and don't stop when someone else butts in. And do talk about your science – not apologetically or tentatively, but – as men tend to do – as if it's the most earth-shattering thing since p53 and prions.

If you want to make a lasting impression on someone who might one day be reading your grant application, reviewing your latest manuscript or looking over your CV for a new faculty position, it is very important to realize that you won't be able to convince anyone that your science is good enough if you don't truly believe it yourself. So do take every opportunity to meet as many people as possible, while keeping in mind that how you carry yourself, what you wear, what you say and how you say it can all send an important message that you're worth knowing – and worth remembering in the future.