Before you get ready to take your shot, look at the background. Try to find something that will contrast or not compete with your subject. if you can control your light, make the background just a little darker than your subject. Lastly, if you can and you don't feel the background is necessary to the image, throw the background out of focus.
This image of Asia Marin (plus size model) was a 20 minute headshot session shot outside of a bus station (that's a bus behind her and the purple is magic).
I was blessed to work with superstar Keira at the Biltmore in Miami. That fountain did all of the heavy lifting for me. It was really bright so I made the background darker and then lit Keira appropriately.
Great shoot with Dee dee (children's author out of Miami) at Wynwood. Again, that background pretty much set me up for success. Her dress just pops against it.
Rage Cosplay does a great harley Quinn and I wanted to find a background that made sense with the character. The lighting pulls her away from the background and focuses the eye.