Someone mentioned the artist Roy Lichtenstein earlier, so here's a little story about how I met him - briefly:
In late 1993, I went over to New York to go to Dylan's four shows at the Supper Club (another little story, incidentally, but not for now). On the next day, news came through that Dylan was to appear on The David Letterman Show that evening. Because of the flight I'd booked, I could not attend the recording but I was able to accompany friends ensconced in a bar next to the Ed Sullivan Theater where the show is recorded. Across the street, Robin Williams was making some film, as I recall. My friends were working all their contacts in Dylan's entourage to get themselves into the Letterman show - and they succeeded, it transpired. One of my Dylan contacts was there and he was also booked to fly home that evening and on the same Air India flight as me. We decided to hook up for the rest of the day, share cab fares and so on. An American friend of his offered to take us both out to eat. So, the two of us loaded our luggage in her car (yes, we'd both checked out of our hotels) and she drove off to the western side of Manhattan and down the road that goes past the USS Intrepid floatring aircraft museum. She had a particular place in mind but, as she got level with the Greenwich Village, she suddenly changed her mind. "I've got a better place to go", she shouted, as she suddenly turned across into the Meat Market district. Now, this area is quite chic, I believe; then, it looked half-derelict and a bit unsavory. We paarked in what I now know to be Ganesvoort Street, across the road from a cafe. In terms of the area, I wasn't prepared to leave my luggage in her car. We crossed to the cafe (Florent was its name) and, as we sat down, our American friend said, "That's Roy Lichtenstein over there". I wanted to get his autograph but played it cool. He was with two younger women, incidentally, and they were seated at a table well away from the front door and positioned so that he could see the whole of the dining area. I kept a discrete eye on the progress of his meal. because I didn't want to interrupt his eating. At what I judged to be a judicious moment, I went to the restroom, which involved passing his table. On the way out (that is, coming from the back of the dining area and slightly away from the direction of his gaze), I turned, apologized for interrupting his conversation and asked very politely if he could sign my notebook. He listened when I said that I'd attended the exhibition of his works at the (old) Tate Gallery in London in the late 1960s and he graciously signed a page in my notebook - unfortunately on the reverse of where I'd written someone's address. I wish I'd proffered a fresh page and had asked him to do some dots or circles on the page around his signature but the autograph was more than sufficient.
Incidentally, I applied exactly the opposite approach when playwright Arthur Miller attended the London opening night of one of his plays at a small theatre in North London - and I was also successful. The circumstances were entirely different and called for different tactics.