Most parents want the best for their children and will go to almost any lengths to see that they get it. They will leave chic Friday-night dinner parties early because Junior has hockey practice 25 miles from home at 5:45 on Saturday morning, or they will spend more they can afford on expensive magicians for Susie's fifth birthday party.

Because my children are now 13, 12 and 9, I can see with hindsight that many acts of parental overindulgence (financial and social) were unnecessary. Here are some of the things I learned: Birthday Parties

The grandness of birthday parties can escalate faster than inflation as parents try to outdo each other. I have known women to rent a London bus and take 25 children out to the Capitol Center for a basketball game, others to take 10 children to the Kennedy Center to see a $15-a-head musical comedy, still others to take a dozen children to dinner at the Lion d'Or. Small and simple is best, plus:

Never buy helium-filled balloons and transport them in your car to the house. When they pop, you may think you've been attacked by terrorists and crash. Regular balloons are much cheaper and cause much less wear and tear on both pocketbook and nerves.

Never rent pony rides for toddlers. It is expensive; half the children are terrified, the other half are bored.

Never drive for more than five minutes with more than five children in the car. You will have a nervous breakdown.

Never have more than six children spend the night on a birthday. We had 10 stay the night of my 11-year-old's birthday. One got homesick, one got a stomach ache, one got hit (by accident) on the back of the head and received four stitches at midnight in a hospital emergency room. Animals

All children love animals and I believe that those parents who refuse to have any pets are cruel and selfish (or allergic). No parent, however, needs to feel obliged to set up a menagerie unless they have a penchant for rabbits, white mice, or long-haired guinea pigs.

Children lose interest in these animals long before the animals tire of this world. Invariably it is Mom and Pop who are left to clean the smelly cages, refill the water jar, and feed the odoriferous pellets to noisome rodents. A few simple rules about animals:

Never have gerbils unless you like them. They are ratlike and they scurry. Their exercise wheel squeaks all night as they work off their excess energy, they knock wood shavings all over your floor and they procreate like mad. The babies look like unborn fetuses for days after birth and ocassionally the mother will eat them (this upsets the chilren). Occasionally she won't (this upsets the parent).

Never allow the children to bring home goldfish they win at fairs and school benefits. The trick is to say "no" before the fair, as it takes a heartless parent to refuse a home to a goldfish clutched proudly in a plastic bag held by a 6-year-old.

Their water must be changed daily; they must be fed (children remember two out of three days) and their outcome is inevitable. They will either fade to a chalky white or develop disfiguring bumps, both sure signs of doom. The day finally comes when the family gathers for breakfast to see a dead goldfish floating to the top of the fish bowl on the kitchen counter. Afterschool Activities

There are two kinds of afterschool activities: the kind parents want children to do (for self-improvement) and the kind children want to do. Many ideas that pop into their heads are merely whims and will go away if you wait long enough.

My list of don'ts:

Don't insist on tennis, piano, ballet, woodcraft, etc., lessons unless the child expresses an interest. Wait until they beg for lessons and you'll save yourself an ulcer and lots of money.

Never take them to cultural events that you suspect might be boring: once they are burned it will be harder to get them to go again. On the other hand, don't allow them to browbeat you into taking them to R-rated movies just because "everyone else has seen it."

Unless you are very rich and can afford to waste up to $100 a night, refrain from taking all children under 10 to fancy French restaurants. The service is slow compared to Roy Rogers; the food often offends youthful tastebuds. You will blow your stack as your 7-year-old slides under the white linen tablecloth, asleep.

Don't buy them clothes that you like, and they don't. They'll look unworn a year later -- because they are. The Entrepreneur

All children go through the phase of wanting to raise money and become financially independent before they are legally able to go out and get a job. All of our money-raising schemes have cost us money. Particular headaches:

Collecting newspapers. Children love to collect newspapers and it keeps them busy and happy for hours. Unfortunately these piles of paper must be stored, then transferred to a car and transported to a collection center. It costs money to have someone from the Yellow Pages clean out your garage.

Selling stationery. My chidren lost money on this deal because they claimed they were "too shy" to go to every door, they lost several orders, and the mechandise was not high quality. I now have boxes of flowered sympathy cards.

Other potential moneymakers that flopped: hawking a clandestine collection of firecrackers, writing and marketing a neighborhood newsletter, and selling vegetables grown in our garden. (They sold the ones we planned to eat.)

Now I'm waiting for somebody to tell me the pitfalls -- and how to avoid them -- in raising teen-age children!