Fireworks photography is unique in that you probably only have one day per year to develop your skill set. And then you forget everything you learned from that experience just in time for next year.
To overcome this, I would suggest the following action items:
1. Immediately after your shoot and as you are going through your photos, write down some notes that you can refer to just prior to your next fireworks outing... ISO, aperture and shutter speed settings, shooting mode (Auto, Manual, Aperture)
2. Review the links below before your next fireworks outing.
Here are the few suggestions that I can pass along.
a. Setup in location that is neither too far nor not too close to the launch site as you want to be able to capture the whole display with the focal length of the lens you are using
b. Use a sturdy tripod to support your camera. Two second delay on your shutter to avoid camera shake
c. Manual exposure - ISO as low as your camera goes, Shutter speed at 10 sec, Aperture wide open
d. Set your lens to Manual focus
e. During the early moments of the fireworks display, tweak your composition by adjusting the camera on the tripod head and the focal length of your lens to include the whole burst in your composition. Also adjust your lens to achieve focus. If you have your composition set and your exposure set, all you have do all evening is press the shutter button when you hear that sound!
f. You are ready to capture your photos
g. Now it is a manner of timing. The 10 second shutter speed (plus the two second delay) usually is sufficient to capture a whole burst if I depress the shutter when I hear the sound that is made when an individual display is launched.
Note to Rick:
Need to address adding foreground interest and ground level displays
Additional resources