i used to never signal.. but got wiser and i do it most of the time now. (mom yelling at me while being a permit driver helped a great deal i suppose.. [fake] )
i always signal when i'm making a 90 degree right turn to let those behind me know to back off, and i'll be turning. it's the worst to have some guy stop in the middle of the road w/ no sig, just to turn right. and if i run into the idiot? i'll be the one getting the ticket!!
i also have a thing against those sitting in a left turn lane with the signals on. i mean, yea yer stopped at red in a left turn lane, why do you have to keep flahsing that amber thing at me, at night to tell me that you'll turn? so i turn mine off when i get settled in the lane.
otherwise, "you have blinker for a reason, it won't kill you to use it", is my motto