Sizes 4-10 are the most productive trout-sized Muddlers, and they can be fished on floating, sink-tip and full sinking lines.

The Clouser Minnow wouldn't make the list of indispensable trout flies in most regions of the country. Along the West Coast, however, anglers fish in sprawling impoundments. They also cast for sea-run cutthroat along saltwater beaches and large rainbows in mountain lakes. In all of these situations, trout feed heavily on baitfish, and Clouser's eyed bucktail is one of the most deadly forage fish patterns. Chartreuse over white, blue/white, pink/white and tan/white in sizes 2 and 6 will cover most situations.

As with most of the patterns listed above, they are very versatile, impressionistic flies. They can imitate everything from an ascending caddisfly pupa to a drowned mayfly to a Yellow Sally stonefly. Yellow bodies represent Rycophilla caddis, Yellow Sallies and pale morning dun mayflies, while green is best when Hydropsyche caddis are present. Sizes 12-18 are standard.

I have heard more than one veteran flyfisher claim that if they were restricted to a single pattern they wouldn't hesitate to pick a Woolly Bugger. With its chenille body, marabou tail and palmered hackle, this is one of the most suggestive flies you can fish. Black Woolly Buggers can imitate large stonefly nymphs, and chartreuse flies are fine dragonfly patterns. When tied very sparsely, it can pass as a damselfly nymph. Brown flies fished on the bottom imitate crayfish. Carry these flies in sizes 4-10. Bead and coneheads are commonly added to Woolly Buggers.

The Griffith's Gnat was created to imitate an emerging midge, resting or struggling in the surface film. Fish it on a long fine leader and let it rest for long periods. Sizes 12 and 14 imitate the large chironomids on many desert lakes, while sizes 16 to 20 are better on most waters.

During late summer and autumn, when subaquatic insect activity dwindles on rivers, trout often shift their focus to terrestrial insects. Along with grasshoppers, ants are a highly relished trout diet item. Most ants are black, brown or reddish, and they can be fished both on the surface and as drowned insects. Sizes 14, 16 and 18 are the most popular. Trout key on ants near grassy banks, in meadow stretches and, especially, around log jams and snags.

There is still a clear advantage to be had by focusing your attention on a handful of proven patterns: Each of these flies is fished essentially the same way, regardless of its color or size or weight. This allows you to concentrate on learning how to effectively present a relatively small number of flies, rather than flailing about ineffectively with dozens of different patterns. And limiting the amount of time you spend thinking about flies frees up time to practice casting, line handling and presentation.