I have three card protectors, and my favorite one has a Gold backing, with Pocket Rockets in enamel on the face. Once in a live tourney an Opponent told me he found my tell, and every time I was going to fold I would have the guard Gold side up on my cards, and every time I had a decent hand I would have the A/A showing.
I had never even thought about this as I usually just cover my cards with the guard until it is my turn to act, sides didn't play any part whatsoever, So for a bit of fun I started to use the A/A face up more often, and sure enough he would fold even before it was my turn to act, because he thought I was going to get involved.
Guards in an on-line game don't exist as there is no need for them, but in a live event I find them invaluable as I have seen players
hands folded and snatched up by the dealer even before the player has had a chance to look at them.
Some players do not like to even touch their cards until it is their turn to act, but if they are over the line on a table the dealer automatically believes they have been folded and will muck them, I will always draw the cards back over the line and cover them with a chip or Guard until it is my turn to act, and when it is my turn, then and only then will I look at my hand. before that I am watching the other players to try and see what reaction they have to what they have been dealt.
When the fun Stops, STOP!