Each year, thousands of anglers across the country take the "great leap" from spinning tackle to the fly rod. For many, the switch is a headlong plunge into this classic fishing form that epitomizes the grace, beauty, and smoothness that angling at its finest can mean.

A fancy spilt-cane rod is bought, a silky $20 line, a reel with a butter-smooth drag. Then comes a leader as long as the house and as fine as a damsel's hair, plus a few dozen exquisite mayfly imitations.

Now the newly decked-out angler is ready to march to the water.

It's a crystalline trout stream, of course. In fact, it's probably one of the most difficult streams in the country - a limestone spring creek. Nothing but the best for our new fly fisher.

But what does this ex-spinfisherman find after investing so heavily in the accounterments of the long rod and traveling a hundred miles to a sparkling trout stream?

Frustration. Pure and simple.

Unless he's a bird of very rare feathers, he'll labor just to punch out a big enough cast to get his way-too-long leader beyond the guides of the rod. Backcasts will drop predictably, costing him dearly as those dollar-a-shot flies snag on branches and streamside shrubbery.

And the trout? Those few that he doesn't spook as he lumbers up to the stream may take a critical glance at his fly before shaking their heads and sinking back into the depths. Even if one does prove gullible enough to suck in the fraudulent insect, chances are it will either spilt the fly back out or snap the novice's tippet with a quick burst of muscle - the final frustration on an ignominious day astream.

There is, thank heavens, a better way to learn fly fishing, a smoother route that will lead in a very short while to these same trout streams all beginning fly anglers seem to hold in such esteem. And it will yield plenty of fun along the way, instead of fuming tempers and busted tippets.

The route is panfish - bluegills, rockbass, redbreasts, even small bass. Anything, just about, except chary stream trout.

Why? Because these fish are forgiving. Trout are not.And most of us need a very forgiving fish when we take up this new form of angling.

Not that fly fishing is exceedingly difficult, or beyond the capabilities of anyone with a smidgen of coordination. But it does take a bit of practice, and the best place to practice is not on a limpid trout stream where shy, discriminating fish are popping up all around, driving you to distraction.

But, on the other hand, a real angling situation is a more interesting milieu for learning fly fishing than a back yard or a sterile "casting pond." On a bream-filled warm-water stream, pond or river you can work on your casting technique and still catch fish your first time out of water.

I've introduced a number of people to fly fishing on the Shenandoah, where rockbass, redbreasts and small bass are abundant and willing to take a fly. All were catching fish within an hour; some even caught a dozen or more fish during their first morning's session on the river.

Other nearby rivers such as the Potomac, Monocacy, Rapiden, Rappahannock, James and less-known streams provide equally attractive settings for taking up fishing. Farm ponds and public lakes such as Needwood, Triadelphia, Rocky Gorge, Burke, Brittle, Manassas and Occoquan are also excellent spots.There are few stretches of shoreline to these lakes that don't have some bluegills and small bass hangling along the banks.

Once you make the plunge into fly fishing, you face a host of decisions. The first is the most confusing of all - what tackle to buy. If you know an experienced fly fisher, drag him along when you do this shopping. Here are some suggestions for an "all-around" outfit that can be used for bass, panfish and, later, trout. Start with a 71/2-to 81/2 foot rod designed for a 5 to 7 weight line. If money's no object, buy a good brand of graphite. Otherwise, fibreglass will do. Forget the spilt-cane wands for the time being.

A single-action, lightweight reel is best, and weight-forward lines cast more efficiently than double tapers. A couple of 71/2 to 9-foot tapered leaders testing three to six pounds at the tippet and a few spools of Maxima or Nyloflori leader material in 3X, 4X, and 5X complete the basic outfit.

For flies you'll want a handful of sponge-rubber spiders and cork poppers in sizes No. 10 and 12, a few wet flies such as Black Gnats or Coachmans in the same sizes, and a streamer or two such as the Black Marabou or Muddler Minnow in size No. 8 or 10.

The whole works, flies included, can cost as little as $75 if you pick a fiberglass rod over a graphite model.You can purchase this year at most any well-stocked sporting goods store, but Barry Servients at Angler's Art in Georgetown can provide unpressured, helpful advice that isn't always available at the chain stores.

Three options are available for learning the basic fly-casting skills: 1) Attend a casting school or clinic; 2) find a patient friend who fly fishes and is willing to teach you; 3) get a book that shows the motions of fly castling and teach yourself. All three methods are satisfactory, since it's not nearly as difficult as novices are often led to believe.

Assuming you've familiarized yourself with the basic motions of fly fishing and can get the line out 20 or 30 feet, you're ready to hit the water. Ponds and lakes are the simplest to decipher.

Find a "fishy-looking" shoreline with some weeds or tree branches sticking up from the water and begin flicking a spider popper or wet fly out toward the shoreline, concentrating on any cover visible. Work the poppers and spiders with lengthy pauses spaced between subtle twitches. Wet flies should come back with a slow, steady retrieve.

On streams and rivers, fish slow-moving shorelines the same way, with similar offerings. Deeper mid-stream pools can be probed with streams and wet flies by casting across and slightly downstairs, then working the lure back slowly while twitching the rod tip.

On either type of water you should be striking into fish within half an hour or less. This immediate gratification of a quarry throbbing on the line will instill the confidence and incentive you need to perfect your casting style, rather than the frustration that's bound to come from a premature bout with a difficult trout stream.

Soon enough you'll be ready to move to fly fishing for trout. CAPTION: Picture, THE WEAPON AND THE CATCH: FLY ROD AND PANFISH. By Gerald Almy.