Hello!
First of all, I still don't know anything about particles, so if I say something that doesn't make any sense jsut ognore
But aesthetically maybe I can help.
My first impression was that the particles were in a perfect line and all of the same size. A few patterns I can think of:
-Make the first one bigger and the following gradually smaller (with random oscilations);
-Also, change the opacity so that the last ones on the line are barely visible (making the opacity oscilate a little could work too)
Also, you can try to make additional layers of particles to achieve some sort of glow effect. Or even sparkles leaving the main trail in random directions.
I'm about to start playing around with particles too.. isn't there some sort of particle editor? it's hard to come up with something visually appealing only with coding.