I will start.

As a general rule no matter if I am folding or not. When someone makes a large raise before me i take the time to watch them during the raise and then when it is my turn i take anywhere from 5-20 seconds to look over at them, until they realize they are watching me, to see how they will react…

Often i do this just to see how the person acts under pressure of a 'hostile opponent'. I feel it gives me a small preview of how this person will act later on if pushed, because i feel most people at the table are non confrontational. Sometimes i even say a word or two. You never know until you try this what people will offer. Sometimes a person will want to chat at you in nervousness or sometimes they will seem to collapse and look away like a scolded dog who was caught biting your favorite shoes.

I will say the caviat of my overall table presence is a factor as i wear shades and am pretti stoic most of the time. Especially toward those on the opposite side of the table as me.