Tried and true flies that I use almost daily during the summer months in Northern Michigan. These flies are tied with high quality hooks, hair and hackle. You'd be hard pressed to find a better deal in your big box or local stores, especially considering the quality of materials. The reason for this is because they are being tied by me. There is no mark up on these flies as is often the case at stores due to the stores having to pay 3rd party tyers.
One of the first major hatches of the year is the Hendrickson mayfly. Don't be stuck on the water, during a spinnerfall, without this fly. Later in the year this fly can be substituted for an Isonychia spinner, when the Iso's are a little smaller. Tied in a size 14. Half dozen - $13, Dozen - $24
The Borchers pattern is a darker bodied pattern that doesn't necessarily mimic a specific mayfly hatch but is a good all-purpose fly for darker bodied mayflies. From May until August this pattern should be in your pack. Tied in sizes 10 - 16. Half dozen - $13, Dozen - $24
Just like the Borchers, your flybox should not be without multiple Robert's Yellow Drakes. Tied in multiple sizes, this is a great searching pattern during the daytime hours and can mimic many lighter colored mayflies. Quite possibly the most commonly used fly in my boats. Tied in sizes 8-16. Half dozen - $13, Dozen - $24
My favorite hatch of the year, the brown drakes, bring big fish to the net. Big fish call for big flies, and these brown drake duns are just the ticket. Tied in sizes 8 and 10 on extra long shanks, it's hard for a hungry trout to pass up on this meal. Smallmouth bass that are familiar with the mayfly life cycle also aggressively take this fly. A simple, durable and effective fly. Half dozen - $15, Dozen - $25
Tied in a wide range of sizes, this fly is my favorite searching pattern when I'm trying to figure out where the fish are hiding in the river during the daytime. Come evening time, match the size to the mayflies that are out and about, and you're bound to catch fish. I always have a rod with this pattern tied on. It can be tied large enough to mimic brown drakes, or small enough for late season isonychias. Sizes 8/10 - $14 for 6, $25 for 12. Sizes 12-16 - $13 for 6, $24 for 12.
Another option for the Iso hatch, or in some shops you'll hear the name 'White Gloved Howdy'. Always a staple hatch around dusk in Northern Michigan, you can expect Iso's to always show up, even if their bigger counterparts, the drakes and hex, don't want to. The quilled body gives this fly a segmented appearance, much like the real bug. Tied on a size 10 standard dry fly hook. $13 for 6; $24 for 12.