Yeah, I'm all for dots on knobs ( if you see what I mean ). Currently have acquaintance with three aeroplanes with different models of radios, each needs the on/off/volume switch to be turned to a different position to achieve the optimum volume, so having ascertained that, the handy bottle of nail polish puts a dot at the - say - 10'0 clock position. No thinking which hairyplane this is today, just turn the knob on and place the red dot at the 10'0 clock position and and Bob's Yer Uncle.
Mrs ExS would murder me if I even looked at her make-up collection, the local $2.00 shop has a variety of colours that she wouldn't be seen dead in, but which serve many purposes -red for the key to the Port fuel cap, green for the Starboard one ( yes, they're different on one aeroplane ) and I also use blue (yes, you can buy blue nail varnish ) for some purpose which presently escapes me but which I felt was important at the time.
The KISS method ( Keep It Simple, Stupid )