This training manual on Advanced Surveillance covers all aspects of carrying out a physical covert surveillance in order to gather intelligence and evidence.
This is an interesting topic to read about, but be warned, it takes a lot of effort and practice time to learn how to do this.
While most of us don’t have the need to know how to surveil, or have any reasons to learn how to beat surveillance, but who knows what will happen in the future.
I remember as a kid acting like I was a spy and trying to sneak around the store and watch my mom. I was not good at it, because I was caught and smacked later for embarrassing my mom.