LAST YEAR:
I got to my location at the SW corner of the BYU stadium for the stadium of fire at 8pm and waited 1hr until people started lighting of personal fireworks
The first actual firework went off at 10:18
I’ll be there again this year barring any unforeseen circumstances.
TIPS:
Use bulb mode and usually shoot 2-5 seconds. Shoot manual and have aperture usually f/9-13
Shoot low ISO
And the obvious… have a tripod.
A remote trigger is awesome, one that does bulb mode is superb.
But if not then use a timer and set it to like 2 seconds… a little more annoying 
almost forgot: a lens that does internal focusing or at least locks or doesn’t creep when shooting a long shot.
Because you will be pointing up.
I usually shoot with a telephoto and focus on shapes.
Mainly because of the location I’m at.
But others tend to do cool foregrounds or backdrops.
The smoke from the fireworks can be your friend but in some cases it might be bad
Oh have a good tripod that won’t creep on you during the 2-5 second shot.
Have lots of battery because long exposure drains batteries.
This is a recap from the pictures I shot last year.
One of the cool things about fireworks is that there is no editing needing to be done on them.
Well except darkening blacks can help in some cases specially with smokey pics
