Just because you don't think you need to use your turn signal in advance doesn't mean it's a safe practice. Doesn't matter if there is no other traffic you can see, some of you are getting older and don't always see that vehicle coming from behind. You should automatically be using your turn signal in advance.
Those of you that think it's a good practice to slow down and block other people from passing you need a driver safety class. You don't know the frame of mind of the person behind you. Our police advise getting out of the way, even if you have to pull to the shoulder of the road. Doesn't matter if you have a gun, the other person could be quicker and faster, and you endangered yourself and any passengers.
When I encounter a person driving slow or fast I try to remember there could be a reason other than stupidity. It could be an older driver that's taking their time and being careful. Maybe the other driver has an emergency. Give the other guy a break, it will only take a few minutes.