Back in the old days--yeah, my days--many controls had distinctive shapes. The landing gear handle ended in a nicely molded miniature wheel and tire, the flap handle was a segment of a flap, the engine levers each had differently shaped (and colored) handles. Obviously we can't do that with six zillion knobs and switches in a 21st century air transport aircraft, but at least there was a time when people were thinking about it.
On the other hand, how many people retracted the gear when they thought they had the flaps? Or leaned the mixture past lean cut when they thought they were dialing the props back?