What's your process for comparing new gear, cables, etc.?

It's a staple of many if not most posts to compare auditory experiences and attribute them to different factors — larger components (room, speaker, amp, dac, etc.) and the rest (speaker wire, cables, power) etc. This is how we choose new gear or compare what we already have.

Given the number of components and how short auditory sensory memory is, any comparison should change the fewest variables possible, as quickly as possible. (And auditory memory is short, even for simpler sounds. We compare using complex sounds and want to judge complex dynamic effect — soundstage, tonality at various frequencies, overall character or musicality, etc.) Doing things quickly is a challenge with tube amps, which must be shut down properly in order to swap things out. Then, they must be turned on and warmed up a bit.

I'm curious how people conduct their comparisons given whatever factors they contend with. Do you take notes? Have a standard vocabulary (e.g. the one in Harley's book)? Use a checklist? Have certain test tracks that you have virtually memorized? And so on. I'd like to know what works for you.

Most of the time, I'm just listening to music and enjoying it. But when I do want to add gear or make a change, it's natural for a critical comparison to call for some kind of procedure. I'm still trying to figure out what procedure can provide reliable, practical information. When my procedure seems too random or complicated, I feel a bit absurd — like I'm just doing kabuki-science!