The lats get a lot of attention, but what's often missing in back training is hitting the mid-back musculature like the rhomboids and mid/lower traps.
Training these muscles will beef up your upper back, making you look impressive with or without a shirt. Having strong mid-back muscles is also crucial for maximizing performance since they're often a limiting factor when it comes to overhead presses, rows, and vertical pulling.
Here are two exercises that'll fire up your mid back:
Do these at the end of an upper-body day as a superset for 3-4 sets each. You'll get both static and dynamic contractions to trigger hypertrophy and strength gains. Your rhomboids and traps will get thicker and fuller as a result.