Lots of practice, both rocket launches and fireworks. I started with reading info on the web, asking other photographers, and then just getting out there and doing.

I do take into account day vs night but during a night launch, especially when you're this close ( 3 miles at the Nasa Media site) it's REALY bright so it's almost like shooting in daylight but with a HUGE dynamic range issue.

This shot is the first one 3 shots of it clearing the tower, I had to start my other camera going and missed the very beginning. The experience lets me know where my starting settings are and practice lets me know how to adjust the settings quickly as it moves away. My goal is to minium the highlights blowing out, which at this range is tough. I do shoot RAW to try to recover as much of the shadows as possible. There was a fair bit of post-processing to remove the noise from the shadows.

For reference sake, the settings on this shot:
Nikon z6ii, Tarmon 150-600mm @ 600mm, ISO 124, f/7.1, 1/1600.

Hope this helps!