Once you’ve found your sound, these are great aides for reproducing it later on.
I have an Epiphone Les Paul Standard 2006 model with Gibson Classic Plus 57 pickups on neck and bridge as well as .015 uF and .022 uF Emerson Bumblebee caps on respectively neck and bridge with 50s wiring. They allow for a broad scheme of tones, while preserving clarity even with the tone tapered down fully, but the non-linear transgression really offers a wide range of interpretation of what your guitar sounds like.
These knob pointers help you quickly identify and remember where you need to be at. The knob-size of the Epiphone-knobs is 24 mm, so most of the other knob pointers with a maximum diameter of 20 mm won’t do, most certainly not when you center the holes properly.
I don’t get why exactly, but when you take off the knobs off of the pots, it’s a good idea to remember what knob went where, so it’s easier to align the knob pointers. They don’t seem to go on the same everywhere.
One thing I know for sure: I only barely had to loosen the nuts with a wrench for them to be finger-turnable. You don’t have to put them on real tight, only a little. When it feels like they’re on a little tight, don’t tighten further.