I remember my grandmother telling me that if I were ever to marry, I should make sure he was kind. But she might just as well have said: "Find yourself a man who's nice to waiters." The way people treat restaurant staff is, I think, a kind of poker tell, revealing a person's character in as long as it takes to say: "I'll have the sea bass." A man (or woman) who is actively unpleasant to waiters is best avoided. Ditto those who patronise them. Just as bad, though, are people who treat waiters as though they're invisible. This is not, as these cretins seem to think, a sign of metropolitan sophistication. Do this, and you might as well be wearing a T-shirt that says: "I'm an over-privileged baboon: cold, ruthless, rude and rather stupid."

Is rudeness in restaurants on the rise? It feels like it to me. Several times in recent weeks, I've watched, appalled, as someone on a nearby table has harangued their waitress beyond the point of reason. On one occasion, in a restaurant I love, I came close to intervening. Why is it happening? I'm not sure. On one level, it's connected to the disappearance of manners in general, a loss of grace that I connect to the rise of the smartphone. But perhaps, too, people feel, in recessionary times, able to demand more. Their conviction that the restaurant needs them more than they need the restaurant gives them licence to bully.

I am not rude to waiting staff. Quite the opposite. I begin by being ingratiating, inserting the word "possibly" – as in, "could I possibly have some water?" – into every sentence, and then, bit by bit, I crank it up until appreciation oozes, brie-like, from every pore. On hearing the day's specials, for instance, I smile and nod maniacally, a look of wonderment spreading across my features as if I've lucked out merely to be listening to such poetic descriptions. Should I then fail to choose one of these specials, I'm careful to sound a touch embarrassed, and when my order arrives, I try to look pleased, yet not too pleased. "You were right," says my chastened expression. And so it goes on. I overpraise. I overtip. I am just so bloody grateful.

I like to think I'd behave like this even if I'd been born into great wealth, a houseful of servants to iron my pyjamas. But it probably has as much to do with having worked as a waitress myself as with manners. When I see someone in a white apron, leaning heavily on a bar, I can't help but wonder about their shift. When did it begin, and when will it end? I think about their feet, too. Do they ache? I worry about their tips, which may be snatched by some higher authority, and about their boss, who might be decent, but might also be a tyrant, and stingy with late-night taxis home.

Long ago, I worked as a waitress in a pub-restaurant in Sheffield. Except that I wasn't only a waitress. I was a barmaid, too. And a cleaner. Each day began at eight o'clock, with the hosing down of the men's urinals. Cleaning the pub took two hours – or at least, that was how much time I was paid for. So I had to be quick. Polish, Hoover, mop, mop, mop. At 10, I went home for breakfast. I returned at midday, for a five-hour shift behind the bar. We were expected, then, to add the drinks up in our heads. Also, to push two new drinks: Taboo and Mirage. I never knew how best to do this. Neither one had anything to recommend it.

At five, I went home for tea. I returned at seven, and worked as a waitress until closing. When I used to ring the bell, I would think of The Waste Land – "HURRY UP PLEASE ITS TIME" – and smile. It was hard to believe, sometimes, that I had another life – though it was this other life that I clung to when the landlord, having discovered that the till was down, told me that my pay would be docked. "Are you accusing me of stealing?" I asked, knowing that if he sacked me, it was only three weeks until my grant cheque would arrive. "If you want to see it like that," he said, jangling the keys to his Ford Escort. There's no one on earth half so jumped up as a fat Yorkshireman with a tiny bit of power.

I've written all this by way of a plea: please be good to your waiter. I know it's annoying when things aren't right. I know it's galling to be given a hefty bill when all night you've been wondering why the table that came in after you was served before you. But waiters are mere messengers most of the time, and it's wrong to shoot them, however bad the news. As you ponder your tip, consider this: you probably don't know the half of it.