If it's true that the best things in life are free, the best things under the tree could cost you almost nothing -- except some time, thought, a card, and a felt pen squiggle or two.

The ideas, of course, are limitless, but here are some to get you started on the gift of a Christmas Certificate.

this entitles bearer to:

Cooking -- Relief from all meals over one weekend.

Sightseeing -- One trip to the Zoo, East Gallery or Space Museum.

Luxuriating -- One breakfast in bed.

Painting -- One entire room.

One quart of elbow grease (approx. two hour's work) -- to be applied to the mess of your choice.

Baby-sitting -- Redeembable for two weekday evenings, one weekend night or taking them out of the house all day Saturday or Sunday.

Escort service -- Two evening's companionship at the opera, a ballgame or other function usually avoided.

Slavery -- Six hours of total devotion to fulfilling your every whim.

Chauffeuring -- Three round trips anywhere in the metropolitan area.

Foot massage -- Soak, rubdown and dry.

Sparkle -- One clean oven.

Favorite dinner -- A homemade meal of favorites, including serivce and clean-up.

Closet organizing -- A complete cleaning and straightening of any cluttered closet or dresser.

Bedtime stories -- Six nighttime tales guaranteed to lull any adult or child into blissful dreamland.

Bathtub scrub -- A thorough cleaning of tub and tile.

Tranquility -- Two Sundays with no watching sports on TV.

Beauty treatment -- Good for a facial, hair cut and set, manicure, pedicure or other treatment of choice.

Laundry -- Six loads, washed, dried and folded.

Wake-up call -- Rise-and-shine service for six important mornings.

Three hours of ski lessons for a beginner.

Back rub -- One-hour back massage.

Shines -- One thorough polishing of all your shoes and boots.

Outdoors clean-up -- Three hours help with your yard work: mowing, raking, weeding, trimming.

One wash of all first-floor windows (outsides only).

Hello-Good-bye -- Two round-trips to a Washington airport, train station or bus depot of your choice (good only evenings and weekends).

Trash -- Relief of garbage detail for one week.

One overhaul of every bicycle in the family: Flats repaired especially.

Car wash and wax (including cleaning out the inside).