PRACTICING the gentle art of flirtation, nowadays, is like trying to make a pleasure excursion on a commuters' throughway during rush hour. You are bound to get knocked about and insulted by grim people anxious to get down to business.

Miss Manners resents hearing the word flirtation, the name of one of life's prettiest occupations, applied to the horrid antics of those anxious to book their lives in one-night segments. A flirt may be audacious, naughty, tantalizing, heartless or outrageous, but would never be guilty of behaving like a hotel-keeper in a fast-turnover joint.

It is a great loss to society. It leaves respectable people with nothing to do at parties but bemoan inflation.

Flirts are, by contrast, happy people who are simple susceptible to additional delights. They flatter the objects of their attention by treating them like the icing on the cake, and not a fast-food meal to be grabbed and devoured because one's starving.

The flirtation is to the compliment what the motion picture is to the snapshot. It lasts longer and it has more words, but it is basically the same idea.

If someone tells you that you are handsome, your response is not to ask what they intend to do about it. And so it is with flirtation. There must be nothing in it to which the participants are held accountable.

Deep glances, accidental touching and uncompromising (but suggestive) talk is the stuff of flirtation. The excitement comes from the fact that although both people know what is happening, neither of them is entirely certain because it is all quite ambiguous.

Proper flirtation -- and it is a proper pastime, or rather an improper one that proper people could properly practice -- is an end, not a means. It is not the beginning of courtship, but a different, milder form of romantic activity for those who do not want, for one reason or another, to be courted. The reason can be as complicated as being attracted by someone who, one suspects, would not improve upon acquaintance; or it can be as simple as the fact that one's spouse is seated elsewhere at the same dinner table. Why should only available people have all the fun?

Actually, judging from the lovelorn section of Miss Manners' mail, available people aren't having any fun at all. They're all full of anxieties about where their next liaisons are coming from, and unable to connect their difficulties with their habits of dumping all their psychological problems on each comer, as an introduction.

The tone should be "Ah, had I but met you earlier -- had I but known that someone like you existed," as opposed to "How about giving it a whirl and seeing if it works?" It is the essence of bittersweet, a pleasure for the sophisticated palates.

But how can one do this among literal-minded clods? Alas, Miss Manners regrets that flirtation is no longer possible when flirts open themselves to the insult of being held accountable for their actions. People who spoil such sport ought to be punished by being condemned to spend their evenings discussing inflation. MISS MANNERS RESPONDS

Q. A gal in our office never goes out to lunch with the rest of us, but always rushes off by herself. Sometimes, she brings a sandwich or a piece of fruit back to her desk, and we see her taking bites from this food, which she tries to hide in a drawer. Her hair is messed up after lunch, and once her blouse was buttoned wrong, although it had been properly buttoned in the morning. Some of us have been wondering what Miss Manners thinks this person might be doing with her lunch hour.

A. Miss Manners thinks that she has probably been out trying on clothes in stores. Miss Manners would rather not know what you think she has been doing.

Q. Last summer, my husband and I stayed a week at a small rural resort hotel. Our bill was $200 (room only). I tipped the maids $6. They wished us a pleasant journey hame and complimented me on my hat. Did I overtip?

How much should the parking lot attendant at a hotel be tipped for bringing the car to the street? Why isn't the maid at a motel supposed to be tipped? I do anyway, about 50 cents to $1 per night, for two persons.

A. It is interesting that most people calculate the size of the tips they give not by judging the quality of services rendered, but by anticipating the behavior of the service person upon receiving the tip. The hope seems to be to give something that does not cause the receiver to scream insults after you, because that would mean it was too little, or that does not bring on a gush of compliments, such as you feel you received, because that would indicate you had tipped more than was necessary to stave off insults.

Your tips are not excessive, and it is possible that the maids were polite by nature and not from obsequious gratitude. Many people have too much dignity to measure their behavior according to the degree of generosity of others.

It is not necessary to tip the chambermaid in a hotel or motel, but a dollar left on the bureau is kind, or 50 cents a night for several nights. Many resort hotels now add a service charge, but otherwise, $10 to $15 a day at an expensive resort is a good tip to be divided among those who help you. You may give 50 cents to the person who brings your car, but $1 is more customary among people who care about their brake linings.