Taking photographs of fireworks can be really easy, just follow the below steps and have fun taking photographs:
1) Wear something warm
2) Get the best spot – always worth asking the organisers where the firework display will be and inform them that you are taking some photographs of fireworks. Generally most organisers are very helpful!!
3) Use a tripod, as the shutter speed is going to be very slow, tripod will avoid any camera shake.
Bhupinder Ghatahora