Not every photo you take at the fireworks display will be perfect. The burst will be too small, the burst will be a bit to the left, the other too far to the right, etc.
Let Layers in Photoshop come to the rescue.
This only works, by the way, if you don’t move your tripod during the display.
Highlight each image that you want to blend in Photoshop Bridge. Clicked on Tools >Photoshop> Load Files Into Photoshop Layers. Photoshop opens the images in a layer stack on the right side. (Lightroom users will highlight all the images, click Edit>Photo>Load Files Into Photoshop Layers.)
Highlight each image, then clicked on Lighten in the blend mode. Then click Layer>Flatten. Click on Filter>Camera Raw Filter to open the image in Adobe Camera Raw so you can tweek it a bit.
Don’t stress it if things aren’t going well at the fireworks display.
Put the camera on the tripod. Frame the scene in front of you. Set the camera’s mode to Aperture Priority. Dial the f/stop to 5.6. Raise the ISO to around 400.
Take a couple of shots. Look at them on the back of the camera. Too bright, then drop the ISO to 200 or 100. Not bright enough, raise the ISO to 800 — though this is usually not the case. Take a couple of shots and repeat.