Yep, there are some tricks
One, shoot from a tripod.
Two, use a trigger (remote) to click shutter.
Three, a nifty trick is to set exposure to 15-30 seconds, place a black card in front of the lens until you see one [firework] shoot up, remove the black card then as it fizzles out put the card back up. Do this until the time runs out. Be careful not to touch the camera or tripod.
Four, do not use a wide angle lens unless you are trying to something specific. Wide angles make the fireworks look tiny (making you have to crop photos).
Five, on long exposures, rattle the tripod a little to see the effects you get.
Six, don't rely on bursts of pictures and hope for the best.
Six, keep your ISO low as possible (long exposures are par for the course).
Seven, use high saturation setting in camera if you are not using a DSLR â€"œ when using a DSLR in post processing set for high saturation.
Eight, shoot in RAW if possible.
Looking at your photos they look too isolated â€"œ you even managed to stop action on one of them. You should try to give some perspective to your photos by adding something like buildings or people in them. Which typically means you'll have to shoot from creative angles and in portrait mode.