Roy & Dave
With gun in hand you use the seam of your pants as a reference point for where to press your palm heel to put the gun in a safe but ready position as you approach a subject from behind to search them or take a weapon from them while they're standing in a compliant posture.
Wes
When doing a cross body parry with stepping of the line you touch the shoulder. This keeps you from pushing your block outside your body. When Wes did his templates there were a number of such reference touches using one's own body for parry, strike, and control techniques. BTW - Wes is really one of the better martial artists I've met at seminar. As one person wrote of him, his memory for martial arts knowlege, forms, and principles is a bit "spooky."

Back on topic...
This is akin to what I think Kanei Uechi was trying to do back in the day when he added the fingertings in the elbow crook before the circle block. He was trying to make a physical reference for a certain posture position.
In the shoken scooping block I was always told to circle past the knee. And I've suggested to more than one student who having trouble keeping their blocks away from their face to do circle blocks wearing a baseball cap. Not perfect - but gets them moving away.
So I'm curious if other folks have found places to put referencing in their training and I'll go over