MOST OF MY Christmases have been joyous, despite portents to the contrary, mishaps, rotten planning. Even the one of 1945 in Hokkaido, the northern island of Japan, when the snow lay roundabout, deep (six feet), and crisp (falling), and uneven (the wind never let up, laying bare rocky outcroppings and piling drifts so the best way out of our buildings was often through second- floor windows). But I was fast accumulating enough points to go home and get out. And we had our first fresh eggs!

Curiously, my father often said that in a sense his best Christmas was in the military. It was in France in the grim, incessant trench warfare of 1916, when somehow a one-night truce took place (he never knew how -- or even if -- it was negotiated) and both sides held off artillery barrages all of Christmas Eve.

Christma has always been such a time of celebration in my families that mishaps were always allayed. The knowledge that the Christmas spirit could not, and should not, be dampened came early and painfully. I was eight and the big family gift was a food mixer with an attachment for extracting orange juice. This was long before the development of frozen o.j., and the only relief from the insipid canned juice was the messy and time- consuming chore of hand-squeezing with a green glass device. When the miracle was unwrapped, I was assigned the honor of collecting all the oranges from the stockings (as opposed to the coal, included to remind us children of our misbehavior, a tradition lost to my children, since they have no first-hand experience of coal -- more on that later) and putting the machine through its first test. I filled a two-quart pitcher of juice and was very proud, until I rinsed the juicer, and dropped it. Smithereens. It took a long while to convince me that it could be, and would be, replaced.

It only seems that most of the tools in my collection were acquired on frantic Christmas eve trips to hardware stores because they were needed to put together toys. But on recollection, the worst required no new and otherwise useless equipment. It was a chest of drawers made of cardboard for my daughter's doll clothing. It couldn't be very difficult, I assumed, and put off the assembly until after midnight.

Then I discovered the instructions ran to ten pages of fine print: fold along line --------- so the inside (not colored) side is out, and fold line so the outside (colored) side is in, then insert Tab A into Slot A . . . By 3 a.m. I had gotten to Tab XX into Slot XX. I peeked ahead in the instructions and discovered I'd be completed at Tab NNN into Slot NNN. At dawn, I extracted a promise from my wife -- never again anything that needed assembly. Agreed.

The next year, bicycles! In factory cartons!

About coal in naughty kids' stockings. It was not an unmixed malediction. You made coal castles, wondrous chemistry with household necessaries. And you still can: In a glass or plastic bowl, put pieces of coal (porous brick, tile, pieces of cement or cinder block may be substituted). To avoid staining, keep the bowl on a protected surface.

Mix together two tablespoons water, two tablespoons table salt and two tablespoons liquid bluing, then pour this over the coal or other contents of the bowl; let stand overnight. Next morning, sprinkle on two more tablespoons of salt.

On the third morning, mix together two tablespoons each of salt, water and bluing; pour into the bottom of the bowl (not directly on the base material). For color, sprinkle a few drops of Mercurochrome, vegetable food coloring or ink over each piece of coal.

By this time a beautiful flowery growth will have appeared. If not, simply add two tablespoons of ammonia.

Free circulation of air is necessary. The formations will develop better in an area where the air is relatively dry.

To keep the castle growing, add more bluing, salt and water now and then. The coal will bloom indefinitely into beautiful rosebuds, coral, crystals and other