Tonight just seemed like a good night to play with a flash unit or two to freeze these incredible birds. Like so many other photographic techniques, I'll just have to suffer through the practice, practice, practice!!!
Focus will always be the challenge, I think, because it's hard to predict where the hummer will come in to -- and I don't presently have a single feeder to give me a smaller area to target. This "Humming Hello" photo was captured as the hummer did a pop-up maneuver and hovered to survey the situation before settling down.
Here he's (she's?) taking aim to insert into the feeding hole. With only one flash unit covering things