Band Pull Aparts
This is an excellent exercise that can be done at home for extra upper back work. Grasp a mini-band or light resistance band and hold it out in front of you with a shoulder-width grip. Your arms should be straight or just slightly bent. From this point simply pull the band apart until your arms are at your sides. Hold this position for a second and return to the starting position.
The difficulty of this exercise will depend on how wide or narrow your hand position is on the band. The wider your hands, the easier it'll be. This exercise should be done for higher reps, around 12-20.