This is a cool exercise to do for your upper back. Attach two mini bands to the top of a rack, pull-up bar or something similar(see picture and use your imagination).
Grabbing a mini-band in each hand, cross your arms (keeping them straight or relatively straight) and pull your scaps together. Hold this position for a second and repeat.
This is a high rep exercise 12+ reps, so don't try using a blue band for this.