I think CPs are one of the more indespensible accessories we can have in our bag, however the end product is subjective. Meaning, kind of like sunsets some people like them heavily saturated, some don’t.
Same wih CPs. How much polarization you dial in, effects the look.
For maximum polarization point your finger at your subject and extend your thumb. You want the sun anywhere along the arc of your thumb as you twist your wrist. Long way of saying maximum polarisation will occur when the sun is 90 degrees to your subject.
Be carefull when shooting skies. CPs can really muck up the tones (imo)., creating an uneven distribution in the blues from light blue to very heavy, dark blue. If you notice that, keep turing the CP until it evens out some.
As Morsie said one the sun starts gettng high, they really start to make tings pop and you get maximum benefits. Other than that experiment, find what you like.
I personally shoot with a CP on 95% of the time, even when thers very little light.
Front and backlit sunrise.



Sing Ray LB Warming CP.
And they come in handy for when you want to slow down your exposure due to the fact they cut the light reaching your sensor by upto 2 stops.

Hoya Pro 1 CP, f13,1/3,fill flash