DEAR READERS: Well, it seems as though we just finished polishing off the Thanksgiving leftovers, and it's time to start shopping for holiday gifts again.

You may consider spending less on gifts this year and doing a little more for the poor and homeless.

However, old habits are hard to break, so if you insist on sending gifts, let me tell you what not to give Aunt Sylvia and Uncle Howard, who don't get around much anymore.

Forget the cologne, dusting powder and after-shave. They probably have several unopened boxes on their closet shelves -- that is, if they haven't already recycled them.

Grandpa doesn't need another necktie, and Grandma doesn't want any more earrings. With the price of groceries going through the roof, older people who live alone on fixed incomes would appreciate a basket of practical goodies. How about small tins of tuna, chicken and ham? Also, crackers, instant coffee, tea, soup mixes and cookies.

People who live in confined quarters do not need more "things," so don't send candy dishes or figurines. And don't send articles of clothing unless you're sure the size is right. Leisure (or "warm-up") suits are comfy and easy to launder. Older folks love them.

Some truly useful gifts: an assortment of postcards, some lined stationery with envelopes and a generous supply of postage stamps. And enclose some felt-tip pens.

Another suggestion: a variety of greeting cards for all occasions. They might want to send someone a nice birthday, anniversary, graduation or thank-you card. Don't forget get-well cards, condolence cards and "congratulations on the new baby" cards.

Should you be tempted to recycle a lovely but useless gift still in its original box, make sure the card to you is not still in the box.

Never give a pet to anyone unless you are absolutely certain that person wants a pet and is able to care for it properly. And if you want to make a hit with someone who has a pet, send a little holiday gift for it (a tin of dog or cat food and bird seed for "Tweetie Pie") along with a gift for its master.

Don't give wine or liquor to people unless you are sure they imbibe. A thoughtful idea: a gift subscription for a magazine or newspaper you know they will enjoy. Candy, nuts and fruitcake make beautiful gifts for people who aren't counting their calories, but have a little compassion for those who are, and lead them not into temptation. Also bear in mind that some older folks have difficulty chewing nuts and caramels.

Another good idea for those living alone on a fixed income: a gift certificate for some kind of service such as window washing, carpet cleaning, taxi rides, barber shop, beauty parlor or dinner or lunch at their favorite place. And (don't laugh) a gift certificate entitling them to a trip to the podiatrist. Because medication is no small item these days, a gift certificate from the neighborhood pharmacy would be very much appreciated. Trust me.

Holiday time can be depressing for people who are alone, so if you know someone who might be alone and lonely, give him (or her) the best gift of all -- an invitation to have a holiday meal with you and your family. Loneliness is the ultimate poverty. -- Love, ABBY

By popular request, Abby shares more of her favorite prize-winning, easy-to-prepare recipes. To order, send a long, business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: More Favorite Recipes by Dear Abby, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)

DEAR ABBY: I would dearly love to see the inside of the homes where my grandmother and parents lived when I was a child. They were farmhouses with no indoor plumbing and, at one time, no electricity. I understand that my grandmother's house has been completely modernized, and I can see from the outside that an addition has been built onto it.

My question: Would it be out of line for me to go to the door, identify myself, and ask to be taken on a tour of the house? I can't call ahead to make an appointment because I don't know who lives there. Also, I'm always on vacation when I'm in the area, and I can't make an appointment for the next week or month.

This is rural country; people are not as fearful of strangers as they might be in the city, and I can tell them enough about their house to convince them that I once lived there.

I have asked a few friends what they would do if a stranger came to their door and asked permission to see their house. Some said they would permit entry. Others said, "No way!"

Abby, please ask your readers what they would say. And why. -- CALVIN IN MILWAUKEE

DEAR CALVIN: Provocative question. Readers?

DEAR ABBY: This is the first time that I have written to you. Maybe you won't think this idea is important, but here goes anyway:

I have to exercise daily. I walk for health reasons. While I was out walking one day, I suddenly realized that I was not carrying any means of identification on me. I also noticed that other people I passed (or that passed me) didn't seem to, either, due to the outfits they were wearing.

I thought that if I passed out or was accidentally hit by a car or a falling object, who would know who I was, or if I needed any special medication due to my condition?

I now make sure that I carry a means of identification on me everytime I leave home. And I hope that you think this is worth printing for people who job or walk. -- ROBERT BRINKMAN, BELCHERTOWN, MASS.

DEAR ROBERT: It is. And I did. Thank you.

DEAR ABBY: In response to "True Story, Palm Beach, Fla." -- the case where a tuxedoed pair of con men made off with the wedding gifts brought to a country club reception -- may I add:

Bringing wedding gifts to a reception is boorish and bad manners. Wedding invitations are always sent a month before the wedding, giving the guests plenty of time to select and send wedding gifts to the bride's home. This not only allows the bride a head start on her thank-you notes (always a headache after the honeymoon), but it frees family members or friends from the irksome job of standing by the gift table at a time when everyone else is having fun. And then there is the massive job of hauling gifts back to the family home.

Let's return to the thoughtful good manners of yesteryear; send the gifts ahead of time. Maybe the following line added to the wedding invitation would help: "Please do not bring gifts to the reception." -- OFF MY CHEST

DEAR OFF: I agree that hand-carrying wedding gifts to the reception places an additional burden on the bride. However, a "line" on the wedding invitation asking that no gifts be brought to the reception would be out of line.

DEAR ABBY: My boyfriend and I have been seeing each other for a year and three months. We're serious about each other and I plan to move in with him eventually. He's seven years older than me, divorced, and has a daughter I'll call Suzy. He doesn't get to see her much, which really hurts him. He has pictures of Suzy all over his apartment, which is OK because it's important for him to remember her.

What bothers me is the picture he carries in his wallet: It's one of Suzy and his ex-wife together. I could understand it if it was the only recent picture he had of Suzy, but he has others of just Suzy that were taken at the same time.

Quite recently, he found some pictures of other guys stashed away in a drawer at my place. I knew it bothered him, so I tore them all up in front of him, hoping it would make him realize that he is the only one for me. Now I feel it's his turn. He has other pictures of his ex-wife, but the one in his wallet bothers me the most. Should I ask him to get rid of that picture, or just pretend it doesn't bother me? -- BUGGED

DEAR BUGGED: Don't ask him to get rid of that picture, and don't pretend it doesn't bother you. Say nothing for the time being, and if you and he are ever man and wife, that would be the proper time for you to ask him to please remove the picture of "that other woman" from his wallet. Like it or not, she will always be the mother of his daughter, so you can't demand that he erase her from his memory.

DEAR ABBY: Some time ago, you printed a short item about the usage of a "guest towel" in the bathroom, and how it wasn't used but should be.

I make these towels and give them for gifts, but I lost the copy I first found in The Wichita Eagle -- and which I love to include with the gifts.

Could you please publish the little poem again? -- MILDRED LUTZ, WICHITA, KAN.

DEAR MILDRED: With pleasure. The author of the poem is Mabel Craddock of Ventura, Calif., who grew weary of having her guests dry their hands on toilet paper, bath mats and even her curtains -- leaving her pretty little guest towels untouched. Here it is:

A GUEST TOWEL SPEAKS

Please use me, Guest;

Don't hesitate.

Don't turn your back

Or vacillate.

Don't dry your hands

On petticoat,

On handkerchief,

Or redingote.

I'm here to use;

I'm made for drying.

Just hanging here

Gets very tiring.

Most teen-agers do not know the facts about drugs, AIDS, and how to prevent unwanted pregnancy. It's all in Abby's new, updated, expanded booklet, "What Every Teen Should Know." To order, send a business-size, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Teen Booklet, P.O. Box 447, Mount Morris, Ill. 61054. (Postage is included.)