1) Can you cast it effectively?
A very common question in muskie fly fishing is, “How big does the fly need to be?” There is no simple answer to this, but if YOU can’t cast the fly effectively, the fly is no good. Bigger isn’t always better. Fish what’s in your casting ability, but don’t be afraid to push your own boundaries. If the equipment can support it, you will become a better caster as a result. Using materials that do not retain water is also important. This is why you commonly see materials like bucktail and synthetics, but not marabou or rabbit strips.
“Effective” is a term that can vary depending on the water your fish. In smaller rivers your effective distance may only need to be 30’. On larger rivers and lakes, that distance could be further. Keep in mind that most cases do not require you to bomb out the entire line. In fact, this can often lead to a poor retrieve and/or hook set. For example, if your drift is quicker due to wind or current, it can affect your retrieve and/or result a bow in your line.
2) Does it hold its profile?
Not just hold its profile, but accomplish that with the least amount of materials as possible. Adding too much material to a hook is the most common mistake I see. Making a fly larger doesn’t automatically mean adding the same materials in the same proportions. The larger the fly, the more important this aspect is…large profile with the least amount of materials. Its Popovics 101. So how do you accomplish this? Material selection helps. Another reason bucktail is a staple in muskie tying. Bucktail is stiff enough to hold a profile, yet doesn’t retain much water. Bucktail is also good as a base to layer softer materials over. The stiffer base helps hold the profile. Blane Chocklett is doing some really cool stuff with that concept.