My 'theme' is with the 'safety' ---
I put most of my collection together using the idea that the safety was either
ON or OFF...
This idea came to me early and I stuck with it.
I encourage others that are beginning a collection to explore this idea, too.
Tang safety; front of the triggerguard; or back of the triggerguard for familiarty with one's own guns.
There are a couple of exceptions, but for the most part, if I pick up one of my guns, I know by feel where the safety is and how to use it.
Long guns have the safety at the
back of the triggerguard...push LEFT to FIRE.
Pistols have the safety on the slide...and go UP to FIRE.
Revolvers don't have a safety ( per se ) but I chose Ruger DoubleActions so I have the same motion for the cylinder pop-out and reload.
This 'theme' may not agree with everyone, but it's simple and works for me!