I use the white scribble tape that is sold for mixing desks, write on it with a sharpie.
For those nice looking but annoying silver knobs where I can’t see the arrow, got circular stickers that come on a sheet in various size and color, stick those on top of the unreadable knob and use a sharpie to make the indicator mark.
I like the idea someone mentioned, tape on top of the knob, set everything where you like it, and draw marks pointing up. For quick recall of a setting that would work great, problem for me is that I tend to mess with my settings so prefer to just see exactly where the knob is pointed.
One of my main uses btw is to make labels for the knobs, those are often nearly impossible to read. Yeah on some pedals I get used to what’s what, on others I’m having to remind myself - is gain left and output on the right, or the other way around?