Fireworks!!! There is something special about capturing the burst of colorful fireworks. Not only is it a timing but also an exposure issue to not over expose the image. Most of the time when I shoot fireworks, there is always that one shot that you know you missed for a number issues.
For the mechanics, I shoot in RAW and start with 5.6 aperture, 100 ISO and 4 seconds. After the first few shots, I gauge the exposure (look at the histogram) and make adjustments. I have pushed the ISO to 400 and 800 to reduce the exposure time for some photos, however, I want to stay with as low as possible ISO since I print my images. I process the images in Lightroom and convert to jpg.