How do I reliably track my targets?

I've recently been working on filling up my Hyrule Compendium, but have not really managed to figure out how to use the

Sheikah Sensor+

To track items in the compendium.

After selecting an entry yesterday, I've had several occasions where the sensor would beep and indicate that the tracked item is nearby, even though I was in the middle of a lake with no chests, monsters or items nearby.

How do I go about using this feature successfully/effectively?

The thing you need to realize is that the sensor isn't telling you that you are near a target, only that you're merely moving in the direction of the target. The better the signal, the more it is directly ahead of you. So if it's beeping at full strength, that means you should start walking straight ahead. If it's not at full but some bars, you should start turning until you could get a better signal. If you have nothing at all, then the target is nowhere near you at all. If you're standing still, then you won't get any feedback, only that the target is somewhere in the area or none at all.

So as you're moving about, keep walking straight as long as the signal is full. If it isn't course correct until it is. You'll eventually reach your target as long as you're able to recognize that you've found it.

there are no targets in the area and you should go elsewhere

a target is in the area but you're not moving or the target is behind you

you are walking toward the target so keep moving straight