How to polish an effect?

Hi! My first post on the forums! I am working on this burst + projectile effect. I want to polish it more. but I don’t quite know how/what it means to polish effect.

Link to a video of the effect I am talking about.

To boil it down to an actual question:
How do I improve the quality of this effect?
What are some usual points that FX artist polish first?

Of course any other feedback or ideas are welcome!
Thank you for reading!