Ok, so I'm totally there (fishing offerings to death). Thanks to other commitments I have a morning at most on a trib. How often do you change things up? Will you work an area with one presentation then cycle through or do one presentation, move on, then come back with the next presentation?
When we talk about presentation, there are actually multiple things to a presentation. For the purpose of this, we'll just focus on float fishing. But you can adapt this concept to other methods too.
1) Bait or lure
2) Shot pattern
3) Line and leader diameter or length
4) Drift speed
5) Float style
Hypothetical situation:
I arrived at a section of the river. For the purpose here, I'll say it is a pool. Using the best judgement based on experience (or lack of), I decided on a bait, shot pattern, line, leader and length, drift speed and float.
I made a number of drift and didn't receive a bite. Now what?
The first and likely easiest thing to do immediately is to change the drift speed. After a few drifts, I should know if:
1) My drift is too fast or too slow
2) My bait is too high or too low
If the drift is too fast, it may mean I have too few shots. If I think I have enough shots, then I can adjust and slow down my drift be controlling with BOTH the rod and the reel to slow down the drift. So the first thing to change in my presentation is either change my shot pattern, or my drift speed.
If the drift is too slow, it may mean I have too many shots, or my leader is too long and it is dragging on bottom. So the first thing to change in my presentation is to either change my shot pattern, or to shorten my lead.
This first decision should be made almost immediately. A few drifts is all it takes to figure it out.
I make my adjustment and still my drift is too fast or too slow. So it may mean I need the right style float. It is now time to change either to a slimmer or fatter float. Getting your drift speed and depth right is more important than finding the right bait or lure in my experience. If my roe bag is suspended 3 feet above the fish drifting at a breakneck speed, the fish many refuse it. If my pink worm is dragging along the sandy bottom getting silted up, the fish may not see it. That is why I always make sure the drift it right first and foremost.
When I am a little more confident that my drift is fine, and still I am not getting hits, then I start to question my bait or lure selection. At this stage, I DO NOT question what type of bait it is, but how it affects my drift. A plastic worm is more buoyant than a roe bag than a beadhead nymph. Is the buoyancy of the bait or lure (or lack of buoyancy) affecting where the bait is in the water column? Did I forget to adjust the lead and shot pattern based on the buoyancy?
At this point, I would reexamine my lead, shot pattern and bait to make sure I have it considered. Maybe I need to change something here. I would make minor adjustments and make a few drifts to see if it will lead to a hit.
If I am certain that my bait or lure is in sync with my shot pattern and leader, then I start to question the visibility of my leader. Is the water too clear? Do I need to use fluoro or drop down in line diameter? If it is necessary, then I make the change. First, I would change up the leader length (increase or decrease in some case), then I would change up the leader diameter.
Aside from visibility, the diameter of the leader can also affect the drift. A thicker line has more water resistance, and thus, get pushed up (lifted up) by water resistance. If I am using a large bait, maybe the effect of water resistance on the large bait outweights the line diameter. But if I am using single egg, or a #16 unweighted nymph, or any small baits/lure, then the line diameter can certainly adds resistance to your whole system.
Similarly, a longer leader also adds extra water resistance to the system. So sometimes, instead of using a longer leader, I actually shorten it to get the right drift.
So changing the line isn't just for visibility purpose. And at times, the changes I need to make is counter intuitive due to the conditions.
If I am still not getting hits, then I would question my bait selection last. Maybe I am using the wrong bait all along. Bait switch is ALWAYS the last for me to change. I believe that fish, in general, is not that picky. If my presentation is done right, they are often more of less willing, especially on the first few drifts. Failing that, maybe it is the bait.
BUT...if I change up my bait, I will have to check again how my bait affects the drift. An aerodynamic, quick sinking, small beadhead nymph will drift faster than a semi-buoyant, large plastic worm. So right after I change my bait, I go through the check list again.
With some experience, you can make these decisions quickly. A few drifts should be informative. In fact, as I work through the pool, my presentation at the head of the pool can differ significantly from my presentation at the middle of the pool vs. the tail of the pool. I am constantly changing my presentation based on the current situation.
For myself, I've learned that if the water condition is perfect and I'm not getting hits in prime spots after a few drifts, I will immediately change things up. If the water is gin clear and the fish are especially wary, I will try to perfect the presentation until I change something up. Sometimes, it may take up to 15 to 20min before I move onto something else, or somewhere else.
Failing that, I throw a large boulder into the pool to piss off the fish