Monaco's Princess Caroline, daughter of former film star Grace Kelly was mentally shopping for her wedding dress and trousseau at this week's Paris ready-to-wear shows. She's apparently narrowed her choices of designers down to two: She was in the front row at Marc Bohan's collection for Dior and at the Yves Saint Laurent show.

Sophia Loren, who has knocked off about 10 pounds and is now a perfect size 10 and very tall and slim, stopped by Dior to pick up some evening dresses to carry her through her personal appearance tour in America for the film "A Special Day." Among her choices: white crepe evening pajamas, white chiffon with gold embroidery and a big taffeta with a boned merry widow top. Women don't mind giving up the freedom of the loose clothes to get back into the tight ones, says Bohan. "Women will suffer for special occasions," he says. (Another fan of the boned top dresses is Bianca Jagger.)

Actually few stars are shopping at the marathon fashion shows. It is hard to imagine playing the star in the crush of buyers, store executives and press. So in the front row at several recent shows have been the presidents of Bergdorf Goodman, Saks Fifth Avenue, Bloomingdale's, Neiman-Marcus, Henri Bendel and others.

One new store "president" in town to check out the fashions is Anne Johnson. The former wife of Henry Ford plans to open a store in California shortly.

Marjorie Schlesinger Dean, chairman of the board of Tobe and Associates, a consulting firm with a weekly report read religiously by store executives, gave a friendly greeting to a tall American man carrying flowers at the Hoel Ritz. She was sure it was the excutive that she sees occasionally from one of her client stores. It turned out to be Bert Lance.

It was like the old days at the Paris couture shows when the invitations arrived for the Valentino show and the Sonia Rykiel presentation both held at exactly the same hour of the same day. At the height of the French couture shows in the 1960's, Pierre Cardin would always pitch himself against Coco Chanel to see who would get the most buyers and press.

Actually, unlike New York where designers are secretive and protective of their own collections, designers in Paris invite their "competition" to their shows and parties. Kansai Yamamoto has attended every fashion show, each time wearing a different hat. Castelbajac, Issey Miyake and Michel Klein were at the Dorothee Bis show and Claude Montana, Jean Cacharel, Castelbajac and Ken Scott were among the designers in the crowd at the party Michel Klein threw for himself at the Disco Nashville to celebrate his new collection. "The designers are my best friends," said Klein. "We admire each other's work and are proud to show our designs to our friends."

Paris is still rumbling about the uninvited guests at the showings like those who got into the Montana show on half a friend's ticket or the sixty or so who snuck in through the kitchen. Inflating the crowd at Thierry Mugler was at least one American textile manufactuers who was using the presscredentials from a north shore Long Island weekly and the New York sportswear manufacturer photographing from the second row at Yves Saint Laurent who had slipped in on the ticket given him, he said, by a friend at France Soir.

Tickets to the Montana show were said to be selling for 50 francs, which is three times the cost of admission to "Star Wars" here.

A few friends had difficulty reaching Val Cook who was with the Saks/Jandel contigent buying French ready-to-wear for spring. She was listed under her real name, Edith Cook. Among those who did find her was Donna Hartmann, wife of the American Ambassador here who invited her to lunch with Nancy Kissinger, who was dressed to the purple.

One of the best free shows in town now costs $10. Pierre Cardin has started charging visitors to his fashion shows, usually a freebie event anyone can arrange through the hotel concierge or by calling the house directly. According to Cardin, the money helps him pay for the best models. "You pay for all forms of entertainment, why not this?" asks Cardin, who said the admission tab has boosted attendance.

Nudity is a strong theme in the Paris collections - achieved with slits artfully cut down the front of garments or up the sides or just about any place that can boldly reveal the body - from every vantage - front or back, top or bottom. Bared bossoms are as nothing to the glimpses of public hair and rear cleavage. Fabrics have never been lighter in weight and more transparant and virtually nothing is being worn underneath. (The whole look is captured in Yves Saint Laurent's seethrough dress of flowered mousseline awash with flowers, far right.) The show at the Crazy Horse cannot be racies than that on the fashion runways here. And with many of the models plumper and more buxom than they ever have been it is no guess as to what's been keeping store presidents in the front rows at the non air-conditiones marathon of showings, sitting straight up in their seats.

Often a current musical theme runs through a lot of the collections. A year ago it was Stevie Wonder's "Isn't She Lovely" that was repeated as a background for the models. Six months ago it wa "Trans-Europe Express." This time it is far more mixed, with music from "Star Wars" and "Rocky" at the shows for many of the nouvelle vogue designers, "One, Two, Three Rock" and "New York, New York" at Yves Saint Laurent and tunes from "Pinocchio" and other children's films to accompany the Alice in Wonderland and other innocent styles.

The frizz is fizzling in Paris. For two seasons it's been the dominant hairstyle for models, a noncoiffure expressing the freest hair style possible - permed and then brushed into a natural style. Now the look has been tamed with braids, sometimes like cornrowing and other times simply hanging down the back of the head. Maniatis is the big promoter here. Young women on the street are also wearing lots of braids, often one long braid down the back of the head with not much concern for controlling all the wispiness in front. A model for Viviane Viterbo, far left, summed up the whole look with her long braid and big vest and skirt. To give credit where it may be due, Saint Laurent showed braids more than a year ago.

Of course it is possible to have both braids and frizziness, too. In fact, one popular way to get the permed hairdo look without beauty salon threatment is to sleep with your hair in the tiniest braids you can make (a friend is needed to make the braids on the top of the head) and then brush them out in the morning. It works best if your hair is damp when you braid it.

It is still the black American models who star in every fashion show including Toukie Smith, Norman Jean Darden, Bethann Hardison, as well as Washington-born Gloria Burgess.