Andre-mz5 has good starting point. Your pictures look prettier when they are in right direction. Down is on the right side.
Longer exposures might get the effect better. And if there are chimneys or islands or something to get the size of the effect, it makes nicer picture. I like to use really wide lens and have ground and sky. The composing is quite tricky thing always.
This image is one of my where I should be doing something completly different but I'm taking pictures with my left hand. There is also the unseen element of smoke and fog.
While normal show might look just OK, with long exposure this might have been bad photo or something really beautiful. And this is something I had to dig from raw.
I've seen nice photos of fireworks taken with Canon dual ISO but it is totally different world and I don't know about that.