Even the world's greatest bargain isn't worth its price tag if you end up pushing it to the back of the closet and not wearing it (or find it months later with tags still dangling).

Essential for sale-shopping is buying something that you can wear at once or stash away to find useful (and even in style) next winter.

One thing is sure: The cost of clothes will go up, particularly the naturals like leather, down, wool. Also, there are many cold days left to wear things that have been marked down to make room for spring fashions.

You might even take along a belt and a pair of shoulder pads when you shop to see how these accessories might improve what is on the racks.

Among the best buys on sale now:

Down coats, a highly practical -- if not slimming -- purchase. And down jackets and vests for kids and men.

Pumps or other classic leather or suede shoes that can be worn year-round. Don't pass up the bright colors, although on the sale racks now, they'll be on the much-wanted list through 1980.

Gold or silver jewelry, sure to cost more tomorrow than today. And pearls.

A great jacket or great skirt that works with what you already own.

Handknit sweaters or the wool to make your own. Well-fitting sweaters seem more modern than the big and sloppy variety.

Leather bags, also possibly in a bright color you might want next season.

Lace-collared blouses. Or just the lace collar.

Pantyhose, always worth having in reserve, and don't miss out on oddball colors and textures to update what you currently own.

Oxford shirts and Shetland sweaters from the boys' or girls' department (already a great buy before markdown).

Cashmere or wool mufflers from the men's department, for men or women.

Down comforters and duvets. (The energy crisis is not about to disappear.)

Longjohns and flannel nightshirts.

Shoulder pads.

Sweater-vests for men to update any suit, and also add warmth.

A classic raincoat to replace the tattered one you own.

And almost more important are the things to skip, whatever the price:

Jackets and shirts with huge collars and lapels.

Skirts too tight, slits too deep.

Heels too high.

Pants too skinny.

Cocktail hats and disco bags.

Anything for a longshot invitation or possible event.

Anything that doesn't fit, which you hope to diet for or grow into.

Anything the saleslady says "looks great," but you're not comfortable in.