Your success will be greatly affected by how well you apply these two elements of this great Sport of ours - Observation and Stealth. The rewards you gain from making these two work in your favour are massively out of proportion to the tiny effort needed to apply them. The penalties for overlooking them are severe but often the severity is missed by the culprit. How do you prove a negative when the unobservant and careless angler is oblivious to the impact of an approach that is not careful?
So, when you next approach a likely looking spot, make sure you do it as if every fish in the river was able to turn you into stone with just one look. Sit down, or at least kneel, or if you must wade, do it without making a ripple and do stop a lot. Watch what is going on. Think it all through and spend time in contemplation. Slowing down may be counterintuitive to you, especially if you are keen to get catching, but you will be surprised at how your catches will not suffer. In fact you will be more satisfied with them, as you see more opportunities. In addition, your stealthy approach and drab clothing will make sure you see more of the world in and by the water. You cease to be a visitor. You are behaving like the residents, so you too become a resident, Homo sapiens sapiens the innocent predator. Wonderfully, the creatures of that world will come and show themselves to you...
It may be a family of stoats, beating the banks for game, or perhaps a vole will swim across and, because you are staying stock still, it climbs out to sample the salad bars of hemp agrimony, whilst sitting on the toe of your wellington! If you are really well hidden, Halcyon may join you, taking advantage of an overhanging branch, so close you could touch it with your landing net. From there, she or he may perch, spy and dive down, right in front of you. For a moment you can see it beat its wings under water, then out it comes, back to the branch to turn the minnow round and with the head showing out of the front of its beak, it zooms away in a flash of blue and copper on an urgent mission to feed its chicks.
Late evenings can bring even more delightful surprises to you when being stealthy and staying observant. Across the stream you may have noticed a little gap in the margin. Now the evening shadow's closing you become aware of a darkening in the gap. It's a hare! It carefully sniffs the air for predators. Satisfied that all is well, it moves forward to drink and then perform a thorough ablution, remembering to wash behind those long ears. In a moment it is back through the gap and gone, but you got to see it.