Wow! Go you, experimenting with long exposure and night photography like that! It’s so tough, getting every little thing to work properly haha. 🙂
Good job culling down the photos to just these 5! It’s great that there’s not a lot of smoke to make them look dull. I like the color combination of #2. The colors + arrangement of fireworks in #4 is just absolutely perfect! That one is my favorite. And the fact that they are coming out from just in-between the trees is great. So intentional looking.
You can decide whether or not you want to put any of them in your portfolio, but it is evident that the fireworks are noticeably out of focus. I usually auto-focus on the first firework, and then switch the lens to Manual focus so the focus distance is the same on all the rest of the photos. Focused fireworks will have a more crisp look to them, like the one attached. To make them thicker, you can open your aperture wider.