Although I'm not Joan Collins I don't generally like to leave the house unless I'm looking fairly together, with some artificial colour in my deathly pale cheeks and maybe a four inch heel to give my confidence a little boast. Yesterday, however, I had to walk about a mile in the rain to pick up a book I wanted and decided to allow myself to sport bad hair and terrible clothes. In my ancient blue tracksuit trousers, funny tweed coat, scrubbed face and scraped back hair I set off at quite a pace into the wilds of Marylebone's dingier corners. I couldn't believe how roughly people treated me. At every turn I was slighted or blanked. I bought a paper and was sneered at. My jolly banter at the bookshop met with short shrift. I waited for about fifteen minutes to be served at the station cafe, even though I was the only person in the queue. I was shocked. It was though some sort of awful paranoid fantasy had been confirmed. I must wear high heels twenty four hours a day or nobody will like me. I knew it all along!

I didn't mind my poor treatment yesterday particularly but my book launch is next week and if people don't treat me nicely on that occasion it might be more than I can take. Dressing for a book launch is tricky. You want to look nice, obviously, but not necessarily your best. Or rather what you really need is to look strong and quietly substantial. Tough and sweet, perhaps, which as we all know is a terrible combination in food but a good combination when it comes to people. At my first book launch nine years ago I wore a cranberry coloured short sleeved A line velvet mini dress which my mother made me (Bless!) which exactly matched the sea breeze cocktails we served. At my second I wore a tiger print pony skin trench coat by Bella Freud (my sister) and peep toe stiletto mules. With the last book I was feeling so vulnerable that I spent the evening in a punkish black Moschino dress covered in silver press studs which, I felt, said DO NOT MESS WITH ME. Yet this year I can't seem to find anything that will do the trick. There are some amazing clothes out there, romantic champagne coloured chiffon layers at Dolce and Gabana, fragile, parma violet, lace-trimmed square-necked baby doll numbers at Stella McCartney, liquid mercury silk lurex at Nina Ricci and ribbons and lace at Lanvin, but it all seems so elaborate. In all these garments- well in the ones I can squeeze into - I looked a bit gift-wrapped. Not quite a Christmas tree but not a million miles from a box of chocolates either. I thought of Dr Sloper's daughter in Washington Square and how scathing her father is about her complicated get-ups. Suddenly buying anything at all seemed impossible.

For a while I wondered about wearing something old instead and treating myself to the beautiful peppermint touremeline ring I've got my eye on at Boodle and Dunthorpe in Sloane Street (was ever a semi precious stone more chic?) or the gold butterfly ring I regularly visit at Van Kleef and Arpels. But in reality these two rings combined cost more than my advance and where's the sense in that?

Finally at Marni I happened upon a delicate cotton sundress with bits of fucia print and silver threads. It's not at all me, too floppy and feminine and not nearly protective enough, and I'd probably only wear it around the house, but it's pretty and casual and a bit humourous. Which isn't at all a bad look.