Jimmy Carter never entered a room, he just appeared. Jerry Ford had a trademark stumble. Jerry Brown is often rock-star-style late, like the night he entered one Washington gay rights fund-raiser through a disco's kitchen.

Ronald Reagan loves flags, bayonets and "Ruffles and Flourishes." His wife likes grand entrances, most noticeable at a Windsor polo match with her six-car entourage before the royal wedding this summer. The queen of England made her own entrance, behind the wheel of her Vauxhall station wagon.

And two high-ranking government officials once made a very delicate exit, surprised by a Cabinet member who found the pair enjoying the office shower.

Important business, this art of coming and going.

In Washington, a town where the illusion of power is power, entering and exiting is less a walk through a door than a performance of self. A good entrance is a must, a vital part of the repertoire of any shrewd Washington player. A bad exit is peril. It can be rude, insulting and a blot on your reputation.

Once a Washington agency chief was dancing with a female employe when he spied the British ambassador's wife waltzing by. When he realized who she was, he followed her across the floor.

"I was left standing there," said his startled dancing partner. "He had a reputation as a social climber, and this confirmed it."

And now, at the start of the capital's fall season, novices, intermediates and even grand champions should pay attention. The following tales of comings and goings offer techniques, tricks and warnings.

The Bob Strauss Entrance

If you aren't entitled to "Hail to the Chief," this is quite fine. Strauss, Democratic party kingfish, enters rooms like a man who's thinking of running for president.

Observe. In May 1980 Strauss arrived with then-first lady Rosalynn Carter at the Women's National Democratic Club. He paused at the door -- but just briefly, like the tease of an appetizer before the main course. With one hand, he held onto Rosalynn's elbow, deftly maneuvering her through the crowd. With the other he squeezed palms, whoomped backs and patted powdered cheeks. A sly Texas grin. And wide-open eyes, registering faces, names and slender women. He never forgets.

"Just talked to the boss," he kept saying on the way in.

"Gotta get her back," he kept saying on the way out, "or her husband will wring my neck."

Seven months later, he outdid himself. Same technique, but this time aided by music and a well-timed one-liner. Strauss made an entrance as guest of honor at his own tribute, wherein the president of the United States actually introduced him to an exploding crowd of 1,000 Democrats and Republicans. The band played "The Eyes of Texas Are Upon You," the Sheraton Washington ballroom shook, the applause was narcotic.

"Fellow Democrats and Republicans," Strauss said, not missing a beat as he bounced to the podium, "I accept your nomination."

The Cocktail Escape

One of the most difficult exits to negotiate is that of wiggling out of a cocktail-party conversation -- even if the person isn't prattling on for half an hour about his work on the Oilseeds and Rice subcommittee. Cocktail parties are never for substantive talk.

"My technique," says Alejandro Orfila, secretary general of the Organization of American States who is an enthusiastic partygoer and giver, "is to use these types of places to see and be seen, to drop maybe an idea or a word. But don't go into long, dragging things."

If you do:

Finish your drink and go get another. Obviously, you can get drunk this way. More important, this is so overused that it smacks of insincerity. The same goes for using the excuse of the buffet table. In fact, this is worse. Only amateurs actually eat at cocktail parties. Have you ever seen a rich, famous person stuffing him or herself on the shrimp snacks? They never eat, the attitude being that first, they are above food, and second, they go to so many parties that if they ate at all of them they would quickly turn into walruses.

Letitia Baldrige, a modern etiquette expert, offers one of her own oft-used tricks:

"If you just can't stand it for one minute longer," she says, "suddenly, in the most sincere way, say, 'I've got to make a phone call. Now, don't you go away. I'll be right back. I want to hear the end of that.'

"Then go make the phone call," she advises, "to make sure. I would sometimes just find out why they didn't deliver the laundry on time."

Another good technique requires a spouse or an astute date. Make a pact before you leave: I'll rescue you if you'll rescue me. That way, when the member of the Oilseeds and Rice subcommittee is telling you about the afternoon's markup, your spouse or date can come up to you and say, "Oh, there you are! There's someone who really wants to meet you, but she's just about to leave." And to the subcommittee member: "You'll excuse us for just a moment?" Then run.

Finally, one painful problem with this training is that now you'll be able to recognize when people are trying to extract themselves from a boring conversation with you. But after the initial pangs of social mortification, look at the bright side. They've done the work for you.

The Late Entrance

This is especially popular among Washington's studied sophisticates, those folks who understand the importance of "just getting in from the Coast," or, much better, "just getting off the floor." At any Washington party occurring while Congress is in session, it is guaranteed that at least one congressman attending will use the "off the floor" line to explain his tardiness.

("In from the Coast" is more prevalent in New York, sounding ridiculous here. "Just back from Santa Barbara," however, is now quite smart.)

Gore Vidal, the novelist who chronicles the absurdities of social Washington, once took the "just back from" line into uncharted territory: Philadelphia. In April, he arrived at a Washington party he was in fact giving with socialite Nancy Dickerson at 8 p.m. -- precisely when the two-hour event was to end. By that time, a group had gathered near the big door of Dickerson's Merrywood estate to wait his arrival.

"He's certainly making an entrance, don't you think?" observed Ina Ginsburg, another socialite and guest.

A good rule of thumb to follow for arriving at a party acceptably late is to step into your shower at the exact time the party is to begin. If you begin to get dressed too early -- that is, on time -- you'll wind up sitting around at home, all dressed up, flipping through magazines and feeling foolish. In fact, you may feel so foolish that you'll actually go ahead and leave -- how awful -- on time.

This is gauche, compulsive, and, worst of all, eager. Furthermore, it seriously startles your host or hostess. "Some months ago," said an unusually prompt partygoer on the literary circuit in town, "I went to a party and got terribly lost and arrived maybe half an hour after it was supposed to start. I felt silly, although I know you shouldn't. Anyway, I arrived at the same time as some other people I know -- and we were the first ones there.

"And they told me," continued this partygoer, "that the previous week they'd arrived 45 minutes late for a party, and the hostess hadn't taken a shower yet."

The Delicate Exit

Useful if you ever find yourself in a situation as hopeless as this one. Several years ago, a man and a woman at the senior level of a government department were passionately in love. Their two separate offices were very close to the Cabinet member's office, which had the shower.

One night, while the Cabinet member was out at a dinner party, the two were working late. Becoming amorous, they slipped into the shower together. The warm water washed over them, soothed them, caressed them . . . All was bliss. That is, until the Cabinet member unexpectedly came back to the office. And heard the shower running. And walked in.

The reaction of the Cabinet officer is not on record, but is said to have been very witty and very acerbic. And the exit of the passionate duo? They toweled dry, and soon after, got married.

The Fast-on-Your-Feet Entrance

Helpful on many occasions. Secretary of State Alexander M. Haig Jr., a man who can ill afford to be slow on the uptake, learned this a few administrations ago.

One day in the Nixon White House, there occurred a meeting of a Bicentennial task force. Then-presidential assistant Anne Armstrong usually began the meetings with a statement, but she hadn't materialized. So Len Garment, then-counsel to the president, asked chief of staff Haig to pinch-hit.

The subsequent events are recounted by Michael Straight, former deputy chairman of the National Endowment for the Arts, in his book, "Twigs for an Eagle's Nest":

"Gentlemen," Haig began in his speech to the meeting, "I bring you the warmest, most heartfelt greetings of the President of the United States and his staff. We are, as you may have gathered, somewhat preoccupied at present as we carry on the day-to-day tasks of administering the government of our beloved country . . . You in this room are dealing with the basic, enduring issues of our society, and are working toward a resolution of those issues in a spirit of courage and dedication that makes our little actions seem worthwhile."

The general continued like this for 10 more minutes, then left, saying the president was waiting.

"By then I was sure of it," Straight wrote. "I cornered Garment when our session ended.

" 'Admit it,' I said, 'the general hadn't a clue when he spoke to us if we were the National Association of Born-Again Baptists or the trustees of the Atchison, Topeka and Santa Fe.'

" 'That's right,' Garment said. 'I was about to open the door when he hurried by me, so I grabbed him.'

" 'You're on,' Garment told Haig. Then he shoved him in."

The Mel Krupin Entrance

You need a staircase for this one. At Mel's, the downtown restaurant where the politically, socially and journalistically aware watch each other eat lunch, the red-carpeted staircase descending to the main dining floor is as central as the roast-beef hash.

"Everybody makes a grand entrance because of that staircase," said Krupin, a man who added the brass railing and understands this town at its gut level. "Everybody gets the feeling of making the Grand Foyer march."

"Everybody" includes regulars like megalawyers Joe Califano, Edward Bennett Williams and Strauss, who can perform the Mel Krupin entrance with or without the staircase.

The technique: Arrive at Mel's, grinning. Pause at the balcony, 30 feet above the dining area. Make sure you're seen. But don't look like you're making sure you're seen. Hold your head high, and look over the faces. Now walk -- but just the first six red-carpeted steps. Another pause at the landing. It's okay to make eye contact here. Be subtle. Now wave. Walk the next six steps to the main floor. Another wave. Some handshakes on the way to your table. Sit down, calm down.

You'll get double points if you're with a well-known member of the opposite sex who isn't a spouse.

The Slide-By

An extremely valuable exit that is, unfortunately, one of the most difficult to execute is fleeing from a party interview with a Washington reporter.

A "no comment" is safe but stuffy. Adopting an everything's-just-fine attitude in response to a question about the federal deficit is also safe, but might make you look foolish. If you run to the bathroom, it will be dutifully reported. Same goes for a screaming rage.

Best bet is a bodyguard or the Secret Service. Second best is an aide who will interrupt and say: "Thank you very much. The senator must move on."

If you don't have an aide or a bodyguard, try a joke. In party reporter parlance, this is called "giving good quote." If you can't think of a joke, adopt an attitude of casual good humor. Transportation Secretary Drew Lewis once did this well.

"You're not going to get any news out of me tonight," he said to a reporter at a January party. "I'll say something stupid later."

The reporter laughed, wrote it down -- and then went away.

Messy Exits

Study the following departures and avoid the mistakes:

Bert Lance, Spiro Agnew, Richard Nixon, H.R. Haldeman, John Ehrlichman, John Mitchell, John Dean, Tongsun Park, Earl Butz, Max Hugel, Nelson Rockefeller, Frank Thompson, John Murphy, Michael ("Ozzie") Myers, Raymond Lederer, John Jenrette, Rita Jenrette, Paula Parkinson, Elizabeth Ray, Wilbur Mills, Wayne Hays, the Democrats, Chia-Chia.