New York — Festive table settings are an important part of holiday entertaining, and most hosts and hostesses are already planning special centerpieces and settings for the busy weeks ahead.
Well-known New York hostess Marjorie Reed has, in fact, been thinking of decorative tables for months as she worked out script, sketches, and photographs for her new book, ''Entertaining All Year Round,'' just published by Ballantine at $12.95.
Mrs. Reed hopes the one lesson readers take from her book is that life is full of reasons to celebrate and that the key to easy entertaining is a natural, personal style; a good sense of organization; and imagination set loose.
Here are her golden rules for giving a great party:
* Plan an interesting guest list that includes people of different occupations, interests, and ages. Send invitations at least two weeks ahead of time.
Plan the theme, mood, or overall look of the party and make sure you have the supplies you need to translate your ideas into reality.
Write out lists of decoration, food, and cooking requirements.
* Do a mental dress rehearsal of your party to make sure you have forgotten nothing. Leave last-minute time for relaxation, calm, and peace.
Select clothing that is easy to move in, comfortable, and attractive, but remember that the host or hostess can always be slightly more dressed up than the guests.
* Always introduce every guest to the others as they arrive. Move from group to group, mixing guests and making sure everyone feels included and important.
Chat, even briefly, with each guest. Keep a sense of humor and never make kitchen disasters public.
* Use lighting and music to set an instant party mood. In the bedroom, decorate the dresser with candles and flowers, not hair spray and yesterday's mail.
Put one decorating touch in the entrance hall or by the front door to make guests feel instantly part of a festive occasion. Flowers, special lighting, or some special arrangement of the season will do the trick.
* Food that is simply prepared and beautifully presented is always best. Don't hesitate to rely on takeout or catered food, if you have tasted it and it meets your standards.
Put your best efforts into presentation of the platter; never bring a plate or platter to the table ''undressed'' with sprigs of parsley, other herbs, or a bloom of some kind.
* Unusual food presentation can transform the simplest fare into exciting dining. Use hollowed-out vegetables - such as cabbages, eggplants, or bell peppers - as containers for other foods.
Use old silver-creamer and sugar sets to hold sauces, silver gravy boats to hold breadsticks. Set casserole dishes in a wicker basket for a change.
* Write out menus and shopping lists as soon as you begin planning the party. Test new recipes ahead of time.
Plan menus that can be cooked ahead of time, then reheated, or rely on cold food. Don't plan a meal that is more than one person can handle unless you can find or hire helpers.
* Increase anticipation by always having a surprise element at your parties. It could be one special decorating touch, special food, a surprise guest.
Tiffany & Co. comes up with elegant table settings throughout the year, but on Nov. 22 the well-known Fifth Avenue store will open its display of ''Hostess Table Settings for the Holidays,'' featuring ideas from such glamorous hostesses as Estee Lauder, actress Angela Lansbury, fashion designer Carolina Herrera, Mrs. Russell Long, Mrs. Sid R. Bass, Mrs. John Butfreund, and Mrs. Michael Kaiser.