How to make fireworks in the sky - making of

There was a real fireworks at this wedding, but when it ended, I wanted to shoot a wide shot with only a couple, without guests.
And then add a fireworks in postproduction, multiply it for a larger scale, darken the sky for more contrast.
As a result, we get awesome shot of fireworks, which was impossible to shoot.

So how it was done:
1. Different shots of fireworks are superimposed on the frame with a couple in several layers.
2. We darken the frame completely. If necessary, you can use the mask to work with the sky in even more detail.
3. Slightly expose the couple for better contrast.
4. Color grading and you're done!