1. When shooting the sun directly (I used 300mm and a Vari-ND filter) ensure the exposure is low enough to see sunspots - and then double check it. I had the correct exposure but bumped the filter ring and can't see sunspots in the image sequence.
2. If the eclipse is low enough on the horizon to include 'foreground' like trees, the horizon line etc, shoot wide enough to capture it for interest.
3. There were a few shots online with the ISS and aircraft in front of the sun. Nice.
4. Consider travel for capturing a totality event.
5. Put a color checker card in view for a controlled test.
6. Consider using a motorized slider / controller for a more interesting timelapse. It will need a platform capable of tracking the sun 'perfectly' or require additional software to stabilize...
7. The processing.org sketch for image stabilization of the sun/moon frames is called 'LoadDisplayImages' (it was based on the similarly named example code). It attempts to find the center of the sun but is somewhat fooled by the crescent shape. I decided not to tweak it any further.
Here are links to the videos: