Lauren Booth: A veteran demonstrator's tips for the first-time marcher

Take sandwiches.

There is no such thing as politically correct fast food and animal rights activists get everywhere. A sneaky burger is out of the question.

Don't try to have a sensible debate with anybody.

Keep any fears about Saddam to yourself. No one wants to know your point of view. Marchers take to the streets to put two fingers up at authority, trample the Queen's grass and smoke spliff in public. Not to rethink their entire ethical position on the Middle East on the basis of what you say.

Don't offer to "do" anything.

It's your first march, so don't get over-enthusiastic and end up with burning arms (from holding too many banners) or, worse, still burning cheeks (when your homemade chant rhyming Saddam with Edam is met with half a million jeers).

Bear in mind your bladder.

More than a million marchers. Remarkably few extra public loos. Take advantage of those you see. And don't drink too much.

Pick your position carefully.

If you want to hear the speeches, arrive early. If you want to get drunk on Special Brew and dance about like a prat, turn up late and head towards the music and the stilt-walkers.

Take lots of cash.

You'll hate yourself for buying 50 right-on postcards, tea-cups showing Bush as a chimp and kids' Che Guevara T-shirts. But you'll hate yourself even more if you don't. Buy them, then bin them quietly later.

Only wear make-up if you're also in a tutu.

March fashion dictates you should dress as (a) a fairy from a regional panto, (b) a teacher from Grange Hill or (c) Germaine Greer.

Don't set fire to the Stars and Stripes unless you want to visit Camp X-Ray.

Now is NOT a good time to test just how few human rights Blunkett and Blair have left us.