Once your streamer is in the water, retrieving it seems like a really simple and straightforward task. Grab the line, hook it under your finger, and just start stripping, right? The problem I often notice is that the stripping is done without any real strategy involved. After the fly touches down, the line is stripped at a pretty consistent rate that doesn't really change throughout the entire retrieve. Does this catch fish? It most certainly does. In many cases, is there a better way to do it? There most certainly is!
For those readers that have experience with conventional lures, I can think of no better example than a hard jerkbait. Just about any retrieve has the potential to work depending on the species and given conditions, but day in and day out I've always found an erratic and inconsistent retrieve to be best. Rather than following a consistent pattern like a jerk, jerk, pause....jerk, jerk pause for the whole retrieve, mixing it up has always proven more effective for me—sometimes to the exclusion of any other retrieval method.
Just like those jerkbaits, I typically vary my streamer retrieve to some degree based on activity levels of the fish and what I'm imitating. Mixing up a retrieve doesn't necessarily mean going faster, it just means throwing in some added "extras" to make the retrieve more appealing.
There's many ways to mix it up, none of which require any special skills except a little added thought and concentration. It can be something as subtle as an occasional little twitch or bump that breaks up a slow, consistent retrieve, to a completely different cadence full of speed changes, different stripping lengths, varying the number of strips before you pause each time, and pausing the fly for varying lengths of time. Speaking of pauses, that can be a big one to use when the fish are lethargic. Just last week I had a bass pick up my fly during a long pause of nearly ten seconds as the fly sat on the bottom. Whether conditions dictate using a slow retrieve or a quicker one, avoiding what I call a "mechanical" or "robotic" retrieve can trigger additional fish to eat.
The one thing I constantly do during the retrieve is envision the fly underwater.
I think about how it's swimming, how it's sinking, and especially how fish may interact with it. I basically pretend a fish is tracking the fly every single second and keep doing things during the retrieve to tease that fish into (hopefully) striking. This is especially important when the fish are in more of a negative mood or don't seem to want to commit. Have you ever actually seen a fish follow a fly for several feet (or maybe even most of the retrieve) only to turn away and disappear? If your stripping was consistent and unchanged all the way through, that might have been the problem. Not only can a varied retrieve trigger a reaction from the fish, but it can also make your fly stand out better if fishing among thick baitfish schools.
Some of the times I can think of when actually instructed to NOT vary my retrieves have been during the guided flats tarpon trips I've been on. As I remember, the guides always ordered a long, slow, consistent strip to feed those fish—and it worked! Another time is when fish are in a frenzy from chum or busting on big schools of baitfish. When it's like that, I just toss in and get that fly moving ASAP! In all other scenarios, I'm always adding a little "extra" to my streamer retrieves. The way I look at it, nothing in the water is ever moving the same way 100% of the time, so neither should my fly. In the case of imitating baitfish, a varied retrieve also makes the fly look crippled or injured which is more likely to draw a fish out to have a look. Whether subtle or drastic, subsurface or topwater, I'm a firm believer that changing up the way a fly is retrieved gets better results!