....bright tail light and a mirror - with no traffic nearby I ride 2 - 3 ft. left of the white line so that approaching traffic sees me in the lane. This tends to slow most drivers down some and causes them to move to the left. I watch the mirror and as they get to a point 150 to 200 feet back I move over to the right. They usually stay to the left and this creates a comfortable separation - especially good on high speed rural roads with light traffic.
Using the mirror I also watch almost every car approach to the point where they are past me - look back, judge the distance, look ahead for obstacles on the road, look back, etc. - I keep the white line in my peripheral vision when looking in the mirror.
I avoid high volume roads.