As a baserunner, keep your eye out for a pitcher who goes into a daze and pitches from the wind-up when there is a base to be taken. In my amateur baseball league, I see this happen at least once a year.
I don't care if you run with a piano on your back or if you are the fastest runner on the team, a pitcher going into the wind-up is a license to steal. No sign needed. Once you see the pitcher's leg drop back (left leg for a righty, right leg for a lefty), take off!
You might think that this is a trivial point, and a waste of time in terms of teaching points for your team. There are lots of fine points like this one in baseball. They all add up. Covering them could mean the difference in close games.