The "bus driver" exercise is where you hold a plate at arms length in front of you and rotate slowly. It's a hugely underrated movement. It's an excellent way to finish the shoulder workout and make the joint more resilient to injuries.
Start with a 10 or a 25 and work your way up to 45 pounds.
How you could stretch out a set by making use of the fact that you can give yourself a biomechanical advantage simply by changing your foot or hand position.