Never telegraph your punches.
By silently, my cell phone is off 99% of the time.
I have encrypted my passwords so they are so badly garbled I have to use cut and paste to log on.
More fun to play the game this way.
Finally, when you notice you are being tailed by someone in a car, and you are in a bicycle, they have a hard time going slow enough to follow you -- especially without being noticed. And I have had that happen.