You do not have to lurch after Tracey Emin's arty entourage at Catford dog track or light Damien Hirst's cigarettes in the Groucho Club in order to evaluate their commitment to art - though it might be revealing. The collector-dealer Eric Franck, who came to this country from Geneva only three years ago and is taking a stand for the first time at this year's London Contemporary Art Fair, Art 98, has adopted the simple expedient of visiting the studios of artists not represented by dealers and inviting them out to eat and drink.
It was Franck who snapped up Tracey Emin's famous embroidered tent artwork Everyone I have ever slept with, 1963-1995. Charles Saatchi, who coveted it for his controversial "Sensation" show at the RA last year, had to dig deep to buy it from him.
Franck says: "If you have a meal or a drink with an artist, you learn a lot that cannot be learned just by looking at their art. Whether the art is good or bad, it's the personality behind it that matters. I need to know an artist for a year or two before I can have confidence in him, and he in me.
"The fact is, up to 95 per cent of art-school graduates give up art to become, say, actors or pop stars. You have to sort the wheat from the chaff."
At the Fair, he is offering works both by "Sensation" artists Gary Hume and Gavin Turk (his was the life-size waxwork of a pop star holding a pistol) as well as by artists outside the YBA orbit (the tag derived from Charles Saatchi's regular Young British Artist exhibitions of his latest acquisitions). Turk's colourful Multiple Signatures, felt-tip on paper, are pounds 850 on Franck's stand.
Franck met Turk when attending the series of annual summer artists' street markets that he organised in Hoxton Square, in the East End - they were called "Fate Worse Than Death" in 1994 and "Livestock Market" last year. There were bands and street theatre. The future Turner Prize winner Gillian Wearing and the future "Sensation" artist Michael Landy sold work at the markets - the sort of event that hesitant first-time art buyers should see a lot of.
Turk told me that when a taxi driver had said to him he wanted to buy art but didn't know how to go about it, he had advised him: "Buy a copy of Time Out and see a lot of art."
That advice is repeated by Gill Hedley, director of the Contemporary Art Society, a vital but under-appreciated first point of contact for new art-buyers. Founded in 1910 to counter the Tate Gallery's fuddy-duddy choice of contemporary art, the CAS donates new art to public galleries and museums, financing its purchases by art trading. At Art 98, the CAS is holding a market of new art by 80 artists in the pounds 100-pounds 2,000 price range - culled by two of its representatives who spend nine months a year schlepping round artists' studios and the growing number of artists' communal "spaces" in search of fresh talent.
"All the works on offer have our seal of approval," says Ms Hedley. So if you have not yet got your eye in, the CAS will, in effect, choose for you. Ms Hedley says, a trifle truculently: "By the time you reach a studio, we have probably cleaned out the best works and have been able to beat the artists down in price because they know we're introducing them to an audience." The CAS does, however, make a point of introducing buyers to artists.
By comparison, degree shows - at the Royal College of Art, say, Goldsmiths or Central Saint Martins - are not such a good bet. True, you might fall in love with artworks that you will cherish for a lifetime, or even pick some winners. But the works are notoriously overpriced by youngsters who may never even get their own studio. Beware the shoe salesman syndrome.
On Thursday night at the Fair, which is sponsored by The Independent, there will be a guided tour as part of a collectors' evening co-sponsored by Bloomberg, the international news provider, in association with the CAS. It is titled "City Initiative" and is aimed at busy professionals with money to spend who are not sure what they like - or even whether they like art. It will be conducted by the Fair's consultant, Lucy Sicks (to book, telephone 0171-359 3535).
At this, the first Fair since the "Sensation" show, prices for YBAs of the "Freeze" generation (the name of Damien Hirst's 1988 show in Docklands, which spawned the YBA phenomenon) will be under scrutiny. Are they worth buying?
There will be no pickled sharks at the Fair, nor any concrete houses, probably, not even any fibreglass children with penis noses. The market for such iconic "Sensation" pieces is among foreign museums rather than private collectors - with the notable exception of Charles Saatchi.
The future rise or fall of the YBA market is dependent upon Saatchi's seemingly bottomless pocket (he is renowned for his power to influence market values by buying or selling en masse. Now he is said to be considering opening his own commercial gallery). Besides Saatchi, the market is being bolstered by the talent for publicity of Jay Jopling of the White Cube Gallery, which handles Hirst, and by an annual pounds 3.5m spent by the British Council in promoting YBAs abroad - where they sell better than here.
YBA is the world's most vibrant artistic movement, characterised by an unmatched sense of irony. It propelled art into media culture, a feat in itself. But art-as-news commands only a short attention span. Five years, 10 years? Its ability to shock has been on the wane since the year of the shark, 1991, when Hirst should have won the Turner prize (he was awarded it the following year). The "Sensation" show had an air of resuscitation. The shark looked tired.
And compared with the shock art of the Seventies, YBA seems tame - a warning for today's would-be buyers. In 1971, it was not a dull dead shark but live catfish fished from water tanks and ritually electrocuted that caused the sensation. The late Lord Goodman, then chairman of the Arts Council, faced angry protesters at the Hayward Gallery, where the killings, an exercise in ecological conceptualism by the Los Angeles artist Newton Harrison, were called off. Spike Milligan broke a pane of glass with a hammer and called for laws to protect the fish.
Then there were the kinky outrages at the Nicholas Treadwell Gallery, such as Mandy Havers's Pink Crucifixion - a hanging, anatomically detailed leather straitjacket, complete with genitals. The Californian holographer Peter Claudius made a 25c-a-go Blow Job machine. And the Franco-Italian Gina Pane performed Action Sentimentale (1973), in which she pressed a row of tacks into the flesh of her forearm. Who remembers them now?
Coasting on their notoriety, the Freeze generation has, so far, found no difficulty selling unsensational works, such as Hirst's spot paintings, which have fetched up to pounds 36,000 at auction. (Few other YBAs have survived the test of the auctioner's block.) White Cube will be offering Tracey Emin's fancy neon signs in her handwriting at pounds 6,500 and will display a life-size bronze maquette, by Antony Gormley, taken from his own body, in the form of his monumental Angel of the North, due to spread its wings over Gateshead this month.
Meanwhile, Saatchi's taste has reverted to painting - ironically, at a time when the hullabaloo over YBA conceptual sculptures and installations has slashed the value of contemporary oil on canvas. The market is bound to follow him. Alongside the familiar outrages in "Sensation", Saatchi showed the huge, splashy paintings of female nudes by 37-year-old Jenny Saville, and has taken to buying the photo-realist landscapes of 26-year- old Rosie Snell. Two of Snell's big canvases are on offer at the Paton Gallery's stand at pounds 3,000 +VAT - her 68in by 48in Gone to Seed and her 31in by 52in Fallow. The Saatchi Gallery is currently showing flat, poster- like paintings of women by the New York realist Alex Katz.
Some dealers in contemporary paintings are praying that Saatchi has had his fill of sensational installations and will stick to painting. Since YBA erupted on to the scene, Andrew Lamont, a Fair exhibitor who opened the first commercial art gallery in the East End in 1985, has had to cut the prices of some of his painters by half. He says: "It has become much harder to sell young artists not associated with the YBA movement. But for them, emerging painters in mid-career - people with both ideas and skill in handling paint - would be getting a lot more recognition.
"The trouble is that people in their twenties, having read the hype in magazines, go to see YBA work to mock, not to applaud. But these are the art buyers of the future. They do not realise that art is accessible to them."
He is offering for pounds 400 a 12in by 16in Irish landscape, Rineen, by 47- year-old Graham Crowley, whose works of the same size sold for pounds 1,000 in the late Eighties and early Nineties. Crowley's work combines lusciousness with subtle detail. He won the London Open in 1995 and was a John Moores joint winner. Lamont says: "He continues to do better and better things, but the YBAs have not moved on".
Keep an eye open at the Fair for other talented non-YBA painters. Their time may be about to come. The Laure Genillard Gallery is offering a triptych of three paintings, Bed Legs, by 31-year-old Dan Hayes, who, three years ago, was offering his naff but meticulous portraits of guinea pigs at a show titled "Multiple Orgasm" at Martin Moloney's humble home-gallery in Lorn Road, South London. Hayes went on to win the main John Moores prize last year with his dreamy Cage Painting, which has over 300 shimmering colours. Bed Legs, inspired by the off-register colour printing of mail- order catalogues, is priced pounds 3,500.
Paul Hedges, co-founder of the Hales Gallery in Deptford - the only one of six artists' spaces showcased by the CAS at last year's Fair that has taken a stand this year - offers the drawings of Claude Heath, done blindfold while he feels objects or people. Saatchi has begun buying him. Prices: pounds 600-pounds 6,000.
A new painting by Jonathan Parsons, whose Carcass, a dissected map in an acrylic case, appeared in "Sensation", is being shown by the Richard Salmon Gallery, another first-timer at the Fair.
One of Eric Franck's non-YBA finds is the 35-year-old metal sculptor, Cathy de Monchaux. She was a contemporary of Hirst at Goldsmiths but did not belong to his social set. She has sold mainly in America, Belgium and France, where Franck met her. She had a solo show at the Whitechapel Gallery last year, and the Tate has bought three of her fetishistic creations that enclose the colours and shapes of genitalia within decorative metalwork. She uses only a saw and a drill. Prices: pounds 2,000 for six-inch specimens, up to pounds 20,000 for big installations.
If you cannot bear the shock of the new, then visit Michael Roosen's big "tag sale" of dealers' unsold stock next Saturday and Sunday in the Atrium Gallery of Whiteleys in Bayswater, west London (10am-10pm daily). Who will carry off Calvin Russell's Paolozzi-like 12in-high leg sculpture, reduced to pounds 860? Who knows, you might find some painterly oils that dealers have got tired of looking at just when they are coming back into fashion
Art 98, London Contemporary Art Fair, is at the Business Design Centre, 52 Upper Street, Islington, London N1 (0171-359 3535). Opening hours: Wednesday and Thursday (10am-6pm), Friday and Saturday (10am-7pm), Sunday (10am-4.30pm). Entry pounds 10, in advance pounds 7.50, concessions (on the door) pounds 5
Tastemakers: top, White Cube will show Antony Gormley's Iron Angel of the North at Art 98, a life-size maquette in iron of his vast sculpture soon to stand near Gateshead. Above, Dreaming IV, a ceramic by Glenys Barton (pounds 5,500 from Flowers East at Art 98). Above left, Tracey Emin's Everyone I have ever slept with 1963-1995, bought by Charles Saatchi from collector-dealer Eric Franck. Left, Jonathan Parsons' oil on canvas Man (from Richard Salmon Gallery at Art 98)
Good buys: top, Dan Hays' oil on canvas Forget will be on sale for pounds 2,500 from the Laura Genillard Gallery at Art 98. Above, Dangerous Fragility (brass, leather and chalk) by Cathy de Monchaux, a sculptor and contemporary of Hirst's from Goldsmiths College: her work sells for pounds 2,000-pounds 20,000. Above left, Kate by Gary Hume; left, Damien Hirst's Beautiful E. painting - not for sale, but others by these artists will be, through White Cube
Howard Hodgkin's Jarid's Porch (lithograph with hand colouring, from Wiseman Originals at Art 98); right, Graham Crowley's Rineen (oil on panel): an example of a neglected artist who is under-priced - pounds 400 through Andrew Lamont
Left, Gone to Seed by Rosie Snell (oil on calico on panel), pounds 3,000 at the Paton Gallery's stand; right, Calvin Russell's Paolozzi-like sculpture of legs is reduced to pounds 860 at the Atrium Gallery, west London