Muhammed Ali was rumoured to rarely ever lift a single dumbbell. Instead he would focus on body weight exercises and resistance training, such as his famous under water shadow boxing.
One of the best body weight exercises you can do, even referred to as the squats of the upper body are tricep dips. They work for all levels and goals, and hit most muscles in your upper torso along with your arms. Use a machine for assistance if needed:
1) Don’t look straight forward, don’t look the floor. Look to a point slightly in front of you.
2) Take a big breathe while hanging with locked elbows & hold it. Lower yourself & come back up. Breathe at the top, not during reps.
3) Don’t let your shoulders roll forward. Keep your chest up & shoulders back. It’s easier on your shoulders.