Putting salt in the sugar bowl is passe. Dumping Jello in the bathtub is a cliche. Asking your victim to return a call from Mr. Lyon or Ella Funt -- with the zoo's telephone number -- will fool only the greatly gullible.

If the old tricks seem too trite, how do you -- if you're in the market for a good laugh -- create new April Foolery? To solve this practical/impractical joke problem, we went to some of America's greatest pranksters (dead and alive) for inspiration.

The trick, says "Candid Camera's" Allen (no relation to Ella) Funt, is to exaggerate a normally frustrating situation.

An example: "It always seems like the line you're waiting in is the slowest. So we'd set up a gag where someone would come into a bank and naturally get in the shortest line.

"That line would suddenly stop moving and the long one would start going like wildfire. So the guy would switch lines, only to find the line he got in would stop. He'd switch again. Then, when he finally got to the front, the teller would close up and go to lunch."

Funt apparently passed on his puckish sense of humor to his writer-son Peter, whose latest book "Gotcha!" (Grosset & Dunlap, $7.95) provides an inside-out-look at practical joking.

"This type of joke originated as a process of getting even," says the 32-year-old New Yorker. "Therefore, it was a 'practical' joke, as opposed to just a funny one."

Among the classics of practical jokedom he uncovered:

Comedian David Brenner: As a kid he loved going into a bank, taking a deposit slip and writing on the back: "This is a stick-up."

"He'd put it back in the pile and secret himself in the bank. An unsuspecting person would take the deposit slip, fill out the front and take it to the teller. When the teller turned it over to stamp it, he'd see the message and there'd be an uproar."

A Floridian heard about and tried Brenner's trick: ". . . in the modern bank the alarms went off, the police came and it clearly wasn't funny."

Actor Tim Conway: Often the butt of practical jokes on the "Carol Burnett Show." The stage hand's particular favorite (during rehearsal) was wiring Conway up for one of her Peter-Pan-style flying skits. Then they'd break for lunch, "leaving him hanging."

The late artist, cartoonist and humorist Hugh Troy, considered by some to be America's all-time free-style practical joke champion: A favorite was buying a dozen newspapers on days when something momentus happened, like the bombing of Pearl Harbor.

"He'd store them six months then enlist six friends to take the newspapers onto a subway car, sit scattered around and start reading. People would see six apparent strangers reading the same newspaper headline and think, 'My God! They've bombed Pearl Harbor again!'"

Notorious joker Abraham Lincoln: As a youngster he was reputed to have painted the ceiling, then held a buddy upside down to walk across the ceiling, leaving footprints over-head.

"Another big joke for Abe and his buddies was to attach a piece of string to a spring in the mattress of a honeymoon suite in a local rooming house.They'd run the string under the carpet down to the lobby and attach a cowbell to the end.

"All the menfolk would sit around the lobby and wait for the bell to ring. The more it rang, the harder they'd laugh."

One of Peter Funt's personal favorites is a prank he participated in for his father's TV show. "My dad always wanted to build an upside-down room, and he got his chance at the Seattle World's Fair."

Carpenters spent a week upending a windowless room in the fair's administration building. "They put linoleum on the ceiling and bolted on a desk, chair, wastebasket and lamp so it looked like the floor. They painted the real floor eggshell-white to look like ceiling.

"To complete the effect they needed someone sitting at the desk. Since I was an athletic 16-year-old at the time, I got the part. They strapped me in with an automobile seat belt, and I had a crew cut so my hair didn't flop down."

The result was so bizarre that "people who walked in developed a protective reaction and tried to treat it as normal. So I'd wait a few seconds for everything to sink in, then casually say, 'I'm thinking of redecorating my office. Got any ideas?'"

"You have to pick your victim carefully," says Funt, adding that he believes today's society is "too humorless. . . . We are no longer in an era when you can give a hotfoot to a total stranger. You're likely to get knifed. . . . But I think people appreciate letting off steam, or being the victim of a gag that does no lasting harm."

Stressing that his suggestions are "a lesson, not a license" for practical jokes, Funt says you might:

Send party invitations to a dozen friends. Tell just one couple that it's a costume party.

Gather a dozen old books. Write a friend's name and phone number on the front cover of each, plus the offer of a reward to the finder if the book is lost. Scatter the books around the city.

Record instructions for leaving a message on your telephone answering machine. Begin with a straightforward, "If you'd like to leave your name, wait for the tone." Then add, "If you want to wait to leave your phone number, wait for two beeps."

Continue complicating things "until there is a minute and a half's worth of instructions to wait for bells, buzzers, beeps." One of Funt's friends "got so frustrated he just screamed into the receiver."

"Reverse the normal. . . . If you put up a sign saying 'Dry Paint,' everyone will want to touch it. And people can't resist it when there's a sign saying 'Keep on the Grass.'"

Actor Ed McMahon once reversed the normal in a friend's apartment by enlisting several people to help move the couple's living room furniture into the bedroom and bedroom furniture (complete with unmade bed) into the living room. "It's a shame," he chuckles, "that no one does things like this anymore."

From Washington funnyman Mark Russell, lamenting that it's not as easy to pull jokes as it used to be: "When we were kids my brother and I put sugar in the salt shaker and salt in the sugar bowl. The poor kids today have no fun switching the saccharin and the MSG. b

"And 100 years ago street kids would try to knock off a rich guy's stovepipe hat. Now they try to knock off the rich guy."

So if you should miss out on the fun today, Russell says don't despair: "Congress loves April Fool's Day so much, they do their best to spread it out over the whole year."