THE SIGNS are unmistakable. The leaves are down; the price of butter is up. From close friends to the most casual of acquaintances the refrain is the same: "Have you started yet?"

Christmas, traditionally cookie time to most, is for me a bit more. This will be the eighth year I, in order to raise money for Children's Hospital, will be baking cookies literally by the thousands. I give them away Christmas week in return for donations from co-workers, friends and neighbors.

Last December I baked my way through 37 varieties -- at 2,500 cookies I lost count -- and spent four weeks in the kitchen. Although I can count on help from a couple of friends and my sister usually shows up in time to get me through the last week, it's a long haul.

Why do all this? Christmas, a joyful, busy season, can be a lonely time. My first year in Washington I knew few people and worked both Christmas eve and day. I baked those first cookies and brought them to work to be busy and to catch the Christmas spirit. It worked.

I've certainly learned a few things about the vagaries and perils of cookies. These I merrily pass on with one caveat: Cookie baking is a time-consuming activity. Small-batch mixing and short baking times mean you never leave the kitchen.

For those with persistence, patience and a touch of nastalgia-tinged madness here are some tips.

Before plunging in always read recipes through first and know the terms and ingredients. For instance, "ground" means fine, almost powder, while "chopped" means small, regular pieces.

Realize that cookies may be baked ahead and frozen. When defrosting, pop the cookies into a hot oven for a couple of minutes to revive them.

Always taste the dough before baking. Remember if dough doesn't taste good, the cookies won't either. But also be warned that there are among us those who crave dough -- actually prefer it to the cookies. You may want to make extra just to keep these types at bay.

Plan ahead; cookies with brandy or other liquors and also some types with honey or molasses must be made early and allowed to ripen.

Organize utensils and ingredients beforehand -- it saves time. If you commit yourself to making a quantity of cookies, you'll discover your own patterns. I hit an efficient, assembly-line sort of rhythm about midway through the four-week project. By making several rolled-cookie doughs ahead of time, I can use small blocks of time for baking one or two batches.

If you prefer wooden utensils and chopping blocks, be scrupulous in your cleanliness. Clean them often with bleach or with boiling water.

Mixing the dough: Most cookies start with a mixture of butter and sugar. Be sure to put your enthusiasm and energy into this step so you can mix in the flour lightly and quickly. Overmixing makes tough cookies.

Spoon and measure flour lightly. When flour appears compact, I sift it whether the recipe demands it or not.

Pack brown sugar firmly into measuring cup.

Always use dry measuring cups for dry ingredients.

Never use whipped butter or margarine. It may just be a prejudice, but to me truly great cookies are made only with good butter. As a matter of fact, butter may be the ultimate secret.

Remember when grating citrus peels, use only the outer, colored layer.

Chill cookie sheets before you put the cut-out dough on them. This allows for even baking and helps cookies keep their shape. Also, always chill doughs before you try to roll them out.

On any given day, flour will hold a varying amount of moisture. Be flexible enough with your recipes to add a little more or less flour to attain the proper consistency. This takes experience gained only by working with different doughs. Always use as little flour as possible.

Remember to roll doughs as quickly as possible so as not to overwork them. I re-roll scraps only twice because I have found the third batch to be tough. One solution for these leftovers is re-rolling them for use as inedible ornaments. You can put holes (for hanging) in the dough with a toothpick before baking and decorate them wildly or paint and spray them with lacquer.

For squares and bars, be sure to use the recommended pan sizes with a 1 1/2-inch rim (or more).

Into the oven: When using decorative toppings that must bake in the dough, brush the cookies with unbeaten egg white and press dough lightly.

Always use flat baking sheets; the higher the rim, the more uneven the browning. Also choose shiny cookie sheets because the dark ones let the cookies brown too quickly on the bottoms.

Be on guard! Some cookies require only 3 or 4 minutes in the oven. At those times even seconds count.

Use unsalted fats to grease sheets.

Experiment. Some cookies bake better on parchment paper.

Few ovens bake evenly -- check sheets and rotate them as necessary. I check my oven thermostat each year; few are accurate.

Cool cookies on a rack; don't stack them up or they'll stick together. If you let cookies cool too long on the sheet they may stick. You can loosen them up by putting them back in the oven for a minute or two to soften.

Decorating the cookies: Decorating the baked cookies is the real fun. Indulge yourself, be silly, fantasize!Get family and friends involved; it's a good excuse for a party. Assorted colors are easily made from any icing recipe and food coloring and commerical decorations are plentiful.

I've seen some pretty wild reindeer and gingerbread men. After tasting five or six varieties, the novelty wears off and decorating them becomes more fun than eating them . . . almost.

Don't despair over ugly ducklings or misshappen cookies; I've found they're often the favorites.

Storing the cookies: Most cookies store well for a week if kept in airtight bags or tins and in a cool place.

Don't store meringue-based cookies with other types; the meringue will dissolve.

If cookies get hard or dry, here are three suggestions: Put a piece of bread in with the cookies (check the bread every day and change it if necessary); halve an apple and enclose it with the cookies; or wrap a wet paper towel in punctured tin foil and add it to the cookies.

Popcorn makes a great packing material for cookies you want to ship.

Now for the cookies: Recipes are everywhere and I experiment freely. When I see a promising recipe, I make up a half-batch to test. The recipes often need adjusting. Relatives seem to be a good source as are friends. Homemaking magazines and newspapers usually have good seasonal assortments.

Every year I combine old favorites with new -- but not always successful -- experiments. And each year I attempt to duplicate my grandmother's Swiss or German honey cookies. A childhood memory of a soft, spicy, honey-brown cake with white icing drives me on -- but to no avail. I've tried, and failed, seven times. Maybe this year. . . . ALMOND CRESCENTS

These are the odds-on favorites. People love them so much I hate to reveal how simple they are. The recipe is my mother's, but variations abound. 1/2 pound butter 4 tablespoons sugar 2 teaspoons vanilla 2 cups ground flour 2 cups ground almonds

Cream butter and sugar until light and fluffy; add remaining ingredients and mix well. Shape into crescents. Bake at 350 degrees on a lightly greased cookie sheet in the middle of the oven for 15 minutes. Remove from sheets and cool for about 5 minutes; then dust generously with powdered sugar. These don't keep very well, but then they won't stay around long enough for that to matter. FRUITCAKE COOKIES

A revelation to me when I first tasted them -- by Mrs. Arthur H. Peterson, who was a fine cook from Romney, W. Va., and Birmingham, Ala. Note: this recipe makes enough to feed several platoons. 1 cup butter 2 cups brown sugar 8 eggs, separated 6 tablespoons milk 6 teaspoons baking powder 5 ounces brandy or dark rum 6 cups flour 1 pound candied pineapple 1 pound dates 1 pound candied cherries 1 1/2 pounds raisins 6 cups nuts 2 teaspoons cinnamon 2 teaspoons nutmeg

Cream butter and sugar well. Add egg yolks and mix again. Dissolve baking powder in milk and combine with brandy. Add liquid, alternating with 4 cups of the flour. Add the fruits and nuts that have been dredged in the remaining 2 cups of flour. Add spices. Fold in stiffly beaten egg whites and drop onto greased cookie sheet by the teaspoonful. Bake 20 to 25 minutes at 300 degrees. Note: These cookies improve with age and should be given at least a week to age. APRICOT FOLDOVERS

You can use any filling you like, I often use different kinds of jam or jelly. Filling: 1/3 cup orange juice 5 tablespoons sugar 4 or 5 ounces of dried apricots, chopped up

Bring to a boil in a saucepan and simmer for about 10 minutes covered. Uncover and continue to simmer until most of the liquid is absorbed. Let cool. Dough: 1 1/4 to 1 1/2 cups flour 6 tablespoons sugar Pinch salt 1/2 cup butter 4 ounces cream cheese 2 tablespoons sour cream

Mix flour, sugar and salt, then cut in butter and cream cheese as you would for piecrust until the mixture resembles cornmeal. Using a fork, work in the sour cream until the pastry holds together. Form into a ball and refrigerate until thoroughly chilled. Preheat oven to 325 degrees and grease sheets.

Working with 1/2 the dough at a time, roll it out on a lightly floured surface to approximately a 10-inch square. Cut into 2-inch squares. Place 1/2 teaspoon of filling on each square and fold corners into middle at a diagonal. Seal with a drop or two of water. Bake 12 to 15 minutes until lightly brown. Refrigerate to store. SWEDISH COOKIES 1/2 cup butter 1/4 cup brown sugar 1 egg (separated) 1 cup flour 1 teaspoon vanilla Flaked coconut Jelly of choice

Cream butter and sugar; add egg yolk and mix well. Stir in flour, mixing lightly. Shape into balls and roll in unbeaten egg white, then in flaked coconut. Make an indentation in center of each cookie and add a little jelly. Bake at 350 degrees for 10 minutes. BROWN SUGAR COOKIES

Your basic, cookie-cutter cookie. 1 cup butter 1 1/4 cups brown sugar 2 1/2 teaspoons vanilla 2 eggs 2 1/2 cups sifted flour 1/2 teaspoon baking powder 3/4 teaspoon salt

Cream butter and sugar vigorously add vanilla and eggs and continue to beat until light and fluffy. Sift together the flour, baking powder and salt and add them. Chill dough. Roll out 1/2 at a time to a thickness of about 1/4 inch. Cut out with cookie cutter dipped in flour. Bake 350 degrees for 10 minutes or until lightly browned. Decorate when cool.