How to Choose Flies for Fly Fishing by Reading the Water

Start with the fish you want to catch and the part of the water column you need to reach. Small dry flies and nymphs are better suited to many stream situations, while larger poppers and streamers make more sense for bass and other predatory fish.

Learning how to choose flies for fly fishing means looking beyond color alone. Fly size, hook size, profile, and whether the pattern floats, suspends, or sinks all affect how naturally it fishes.

The examples below break down those choices so you can match the fly to your target species, the depth, and the water in front of you.

how to choose fishing flies 1

common types of fishing flies 2

fly fishing target species 3

fly fishing hook size guide 4

practical fly fishing skills 5

Topic	Details
Dry flies	Adams #10; Royal Coachman #10; Royal Coachman #10; Caddis #10.
Nymphs	Caddis #16; Pheasant Tail Nymph #16; Hare’s Ear Nymph #16; Stonefly Nymph #16.
Wet flies	Black Gnat #10; Blue Quill #10; Shaok Quat #10; Black Gnat #10.
Streamers	Woolly Bugger #4; Clouser Minnow #4; Leech #4.
Hook anatomy	Bend, shank, hook eye, gap, barb, point, and throat.
Illustrated hook sizes	#24, #26, #16, #1/0, #2/0.
Trout	Hook sizes shown: #10, #10.
Salmon	Hook sizes shown: #24, #10–#2/0.
Pike	Hook sizes shown: #24, #16–#2/0.
Saltwater fish	Hook sizes shown: #/B, #10–#2/0.

Fly type	What it imitates	Presentation and key characteristics
Dry fly	Newly emerged adult insects or insects that have fallen onto the water, such as mayflies and caddisflies.	Floats on the surface, allowing the angler to watch fish rise to take the fly.
Wet fly	Drowned insects or emerging aquatic insects.	Fished below the surface; a versatile choice for exploring streams.
Nymph / pupa	Immature stages of aquatic insects.	Fished near the bottom or in the middle to lower water column. The image states that more than 80% of a fish’s diet comes from below the surface.
Streamer	Baitfish, leeches, or large crustaceans.	Generally larger patterns, typically used to target large predatory fish.

Target group	Species listed	Main guidance
Small stream fish	Chinese hooksnout carp, Taohua, Xishiban, rainbow trout, brown trout.	These fish readily take insects, making flies especially effective.
Local predatory fish	Topmouth culter, Mongolian redfin, lake skygazer.	Early-morning and evening feeding windows can produce back-to-back catches.
Bass	Bass.	Use frog-imitating poppers or large streamers to trigger strikes.
Saltwater fish	Sea bass, tuna.	The image emphasizes that suitable tackle expands the range of species anglers can target on the fly.

Target group	Species	Hook sizes s	Practical guidance
Small stream fish	Chinese hooksnout carp, pale chub, Taohua.	#16–#22	Use very small dry flies or micro nymphs that fish can take whole. Focus on spotting fish and making accurate casts.
Local predatory fish	Roughskin sculpin, large Chinese hooksnout carp, Xishiban, small trout.	#10–#14	A versatile size range for stream fishing. Use wet flies or nymphs with steel bead heads to get below the surface while matching the mouth size of the target fish.
Large, aggressive fish	Largemouth bass, topmouth culter, lake skygazer.	#2–#8, or larger hooks such as 1/0	Use large poppers or streamers. Choose heavy-wire hooks to resist bending under a powerful fish’s pull.

Topic	Conditions or location	Guidance
Choosing a dry fly	Fish breaking the surface with insects flying overhead.	Tie on a dry fly to draw surface strikes.
Choosing a nymph	No visible surface activity.	The image states that fish are holding near the bottom. Turn over a streamside rock, check the insects’ colors, and fish a matching nymph below the surface.
Choosing muted colors	Sunny weather and clear water.	Use brown, black, or olive patterns.
Choosing bright colors	Overcast skies or murky water.	Use patterns with flash or brightly colored bead heads.
First target spot	Slow water behind large rocks.	Place accurate casts into the slower water.
Second target spot	Current seams and back eddies.	Target the boundaries between fast and slow water, along with areas of reverse-flowing water.
Third target spot	Shaded water beneath overhanging trees.	Cast into the shaded water under the branches.
Casting accuracy	All three target spots.	The image emphasizes precise placement, stating that flies are lightweight and fish will not chase them far.