Some get it queuing for the Harrods sale. I've heard rumour of people stricken outside the first day of the Next clearance: a fluttery, tight-chestedness; an intense craving; you feel it deep in your loins - a need, a yearning: "I must find that thing. I must buy that thing." Shoppers' desire. And I know it well, because I have it in charity shops. As I creak open the door of a suburban Age Concern, and breathe in that inimitable charity shop smell - the sort of dusty, mothballed clamminess - my heart quickens.
I scan the room, slightly breathless, taking in my targets. My beeline is always for the bric-a-brac shelf: I'm on the hunt for handmade pottery, spongeware milk jugs. Like a pro, I scan the offerings, and then I move onto the clothes - I'm looking for vintage-that-doesn't-know-it's-vintage: cotton Seventies smocks, Indian block-printed kaftans, Arran jumpers, men's cashmere - I can spot them instantly among the sagging French Connection wrap cardigans and shiny Karen Millen boleros. I fillet out the gems, moving swiftly around the shop, from rail to rail. I never try things on, because charity shopping is about risk taking (and the changing rooms are always crap).
In 20 years of dedicated thrifting, I can say with complete confidence that I have never knowingly passed a charity shop without going in. I often miss trains and am late for lunch dates because I've happened upon a British Heart Foundation. I just can't help myself. I am obsessed. I have a wardrobe bursting with clothes others have rejected (although I score only the good stuff - no tatty second-hand Primark, thanks), and my kitchen shelves are heavy with crockery scored for pennies. I like the creativity and uniqueness of dressing from junk shops - the clothes find you, rather than the other way round - and a table set with mismatched plates and glasses is by far the most welcoming kind. Who would prefer to own an entire wardrobe from Marks & Spencer, and a set of blue-and-white Wedgewood over a beautiful and characterful collection of gems collected from far and wide? Well, I wouldn't.
And so I wrote a book celebrating that kind of look. The Set Table: the Art of Small Gatherings is a guide to making a table look really lovely with scant resources (old china, wild flowers and candlelight), and is filled with tips on how to repurpose what you might already have in your cupboards and unearth beautiful things for your table from charity shops. Here, exclusively for The Huffington Post UK, are my six rules for thrifting:
1) Imagine things out of context
On a crowded shelf of mawkish figurines, or a rail of sad-looking nylon Nan frocks, you must try to see each item as an individual. Pick up every piece and imagine it out of context: in a chic interiors shop, say, or hanging in the window of Matches. Things which look tatty and unloved in a junk shop sometimes just need a bit of styling. Stand back, squint, and imagine how it would look somewhere really chic.
2) Stick to a theme
As all thrifters know, you only get the goods if you go to charity shops all the time. Because mostly, lets face it, they're not filled with Ossie Clark. You're more likely to be fishing through hanger upon hanger of bad jeans to find that occasional jewel, so you must pop in regularly and be prepared to leave empty handed almost always. Finesse your search (and make quick work of the rummage) by being clear what you're looking for. Perhaps it's sherbert-coloured crockery, vintage children's clothes or hand-knits - decide on your hit list, and stay focused.
3) Turn things inside out
Apart from 80s Laura Ashley (which I love), I never buy high street clothes second-hand - what is the point? So the very first thing I do when I alight upon something I like is to check the label. If I've never heard of the designer, this is a good thing. If it says, such-and-such Made in France or so-and-so Made in Italy, even better. Then I turn it inside out and look for a care label. I am looking for 100% wool or 100% cotton. With crockery, I look at the base: great pottery companies promise quality: I'm hoping for Spode, Royal Worcester, Royal Doulton, Denby.
4) Don't be icky
I understand the squeamishness people have about thrifted clothes. The sort of dead-person waft about it all. I love junk but I also love that fresh, tissue-wrapped deliciousness of new clothes. So everything I buy from the charity shop gets washed as hot as possible before it makes it into my wardrobe or kitchen. If I can't wash it hot, it needs to be dry cleaned. And note: if it smells bad in the charity shop, the rot may well have got so deep into the fabric that you'll never get it out. If there is even a slightly bad whiff about it, leave well alone.
5) Never buy shoes or bags
Second hand shoes (along with underwear, but that goes without saying) are a step too far. The imprint of someone's big toe, the sag and bag of the leather where it's strained around their hot feet - I just don't have the stomach for it. And as for bags, I have a theory: no woman would give a handbag to charity that she loved and used. She'd keep it. She's never going to be too thin or too fat for it, so the good bags in the world stay in women's lives. The bad bags - the plasticky ones, the uncomfortable ones, the mistakes - they are the ones that end up in the junk shop. You'll get it home and it will be instantly obvious why she donated it.
6) Think about location
Contrary to what you've read, posh areas often have the worst charity shops. And I mean worst for people who love to rummage. This is because so many people have written about how great charity shops are in, say, Chelsea, that these places have, sensibly, wised up, and now charge proper, vintage-boutique prices. The charity shops in ritzy parts of town have proper window displays - always so off-putting for a true junk hounds like me. Instead, you need to target retirement zones: East Sussex and the south coast, the West Country. But the real joy of charity shopping is that you never really know what you're going to find - it's always a gamble - and that, for me, will always be the appeal.