And by "in the skies" I mean: dramatic skies. Perhaps this is a sign of my lack of creativity... But my favourite days of shooting (and subsequent photographs) are those where the light conditions are atypically good. With exceptional light, which is generally outside of my control, practically any passing bird creates a better photo opportunity than the combined opportunities presented on an "average" day.
The images in this post were made during a ~35 minute window on Oct 17, 2017. All manner of birds were flying under stormy skies, with breaks in the cloud providing irregular bursts of light. Songbirds were generally flying the "wrong" direction (away from the light), but ducks were crossing at 90 degrees and provided the most opportunities (albeit somewhat distantly).
In an extreme case of luck, an adult Bald Eagle (as shown in the title card and below) came cruising along quite close, and did NOT notice I was present until I had my camera ready! And managed to do an odd yet interesting evasive roll while I had it in focus. AND managed to conduct said roll while sunlit, in front of a sunlit cloud background, at a suitable light angle... No real planning involved, other than lots of previous practice (regardless of light conditions) which might have helped nail the final shots.