I don’t mean get your rival in trouble at school by stuffing the team mascot in her locker. I’m referring to the use of body parts, doorways, trees, windows, landscape, anything that brings attention to the subject.
The frame can be either in focus or blurred. It can take up most of the picture, or it can exist in the periphery. The goal is to emphasis your friend, not the framing device, so make sure it doesn’t overwhelm her.
Be creative, and always be on the look out for new possibilities.