I can see a bad situation coming (trucks) when I have a mirror.
I don't use a mirror (or a helmet) around town. STUPID.

In Montana, where they have few shoulders on state highways I learned a trick from some Europeans.
When I see traffic coming up behind me at 60 mph I get out into the center of the lane.
They slow down to alot when I'm in the center of the lane, then I move over to the right and allow them to go around me. This worked great! It prevented cars or trucks from trying to sqeeze by be at 60 mph. Hugging the right side of the road increases the risk of getting clipped.