I was in the middle of doing ‘barbell twists’ (barbell in a corner, weight on one side, grip the end and rotate up) when I discovered a pretty decent shoulder workout.
Similar positioning --place one end of a barbell in a corner and load weights on the other. Now lift the weighted side to chest level and lean forward, forming a lopsided A. Press upwards.
That’s it. Rather like an extremely close grip nearly vertical incline press, except with a bit more stability work. Give it a shot if you’re short variations.