The truth is, a strike indicator tells so much more than just whether or not a fish has taken the fly. One of the most important things an indicator can tell is whether or not an angler is getting a good drift.
Even experienced anglers that know what a good drift looks like will use reference points as an aid. One thing that I always tell anglers when I’m teaching them to learn what a good drift looks like is to watch the bubbles, or white water, in relation to their strike indicator.
The bubbles, or white water, floating on the surface of the stream are a great indication of how surface currents flow regarding their direction and speed. The currents underneath the surface of the water are not always exactly the same as surface current, but most times they still serve as a great general reference.
In order to use these bubbles to indicate whether or not your getting a good drift, pick the closest bubble or foam line to your strike indicator when it lands. Your strike indicator should follow the same path as these bubbles, which means they are drifting in the same current.
If you see your strike indicator drift in a different direction than the bubbles do, then you know that you are getting a drift with drag. You will also be able to notice drag if your strike indicator starts by drifting in a particular bubble line and transitions to another bubble line as the drift progresses.
In order to correct this you may have to add or subtract the length of line you are fishing, try landing your cast in a different spot that is easier to reach, or stand in a different position.
Using these tips for your strike indicator will help you know whether or not you are getting a good drift, which will help you put more fish in the net. Good luck.