Styling and shaping is an art even the finest hairdressers admit has taken them a lifetime to master; the most honest add, "And I'm still learning."

Steal from your piggy bank if you must to finance an expert cutting. (Perhaps in the simple act of trying to carve out bangs you've already discovered the folly of putting scissors to your own hair.)

As complex as the fine art of hair cutting is its vocabulary: scissors cuts, razor cuts, heat cuts, sculpture cuts, taper cuts, blunt cuts, layer cuts.

Basically there are two schools of hairdressing, the scissors men and the razors men, and each will defend his chosen tool to the death- of your patience. Still others use both, scissors for shortening and razors to give a feathery feeling to hair tips.

Both tools do beautiful jobs in the hands of masters. Actually, most hairdressers cling to the tool with which they first learned to style hair. So don't judge your stylist by whether he uses scissors or a razor but rather by the results you see on your own hair.

Yesterday's thinning scissors are practically one with the marcel - disappeared. Today's shape cutting is based on tapering and layering. Even apparently straight bangs are never cut straight across but are tapered and layered to hug the head. Coarse, thick hair is generously tapered and layered. The same technique used in moderation buoys fine hair.

LAYER CUT: Leaf-like, it encourages hitherto hidden curl, brings out the natural life of hair. It is the ideal background for a waved setting.

TAPER CUT: There are many variations of the taper cut. Most hairdressers prefer to taper cut while hair is wet so that the natural curl or permanent wave shows to advantage.

Many hairdressers use scissors on fine and medium hair, razors on coarse hair. Each strand is held out from the head at a 45-degree angle and cut with a slithering motion on top or underneath. Hair is usually cut underneath if a smooth contour is desired.

The majority of taper cuts involve backcombing, which shapes the hair and removes bulk. Lighter hair curls more, lies better and is more easily controlled. Ends are carefully tapered so they blend well together.

SCULPTURE CUT: This follows the natural curl of the hair and usually does not require any setting after the cut. Simply push hair into place with fingers. Best results are achieved on coarse hair. But good results are attained on all but very fine hair. Hair is usually cut wet with a razor. Hair is sculptured to the head in layers and tapered all around.

BLUNT CUT: Hair is cut straight across with scissors. Used on very thin hair to produce body. Sometimes, as a softening variation, the strand of hair is twisted and then cut to produce a less blunt, more easily blended end. Can be contour cut or shaped layer on layer.

How often should you have your hair cut? The average woman's hair grows approximately one half inch a month and usually more in summer. This much needs to be removed monthly as it tends to make hair heavy and will drag down a good setting.