Mine end up actually being incredibly personal. For the most part my personas have always tended to represent emotional states I was in at the time, the things I was going through and how I was dealing with it, I guess because I've always kind of defined myself by them. My earliest attempts of course I'd say are probably exceptions to this.
First up I'd say is Starlight Savannah, who is highly inspired by Star Catcher. I consider her to be my first persona these days, because I remember her being based on my daydreaming at the time, but I think at the time I didn't know yet what personas were.
As soon as I did learn about personas I created Snowbee, but likewise she didn't last long. I made her but she didn't really seem to fit. Honestly I'm not even sure where the idea came from, I think I had just come up with a random name I liked and gave her symbols that fit it, so none of it really had any meaning apart from being pretty.
I think I just played around with different coloring sheets for a while, trying to figure out a design, but none of them even stuck well enough to be given names. I kinda had an "emo phase" in the middle of that too, but I'd prefer to kinda just skip over that part.
Next then would be Canvas, who was very much a "reset", a "blank slate" mixed with being an artist, and represents the start of my life as I know it now. She is kind of the start of my "reincarnating persona" idea, where my different personas are all actually just one pony being reincarnated, with each new version still holding the old one's memories.
After Canvas is Lantern Light, who I created after I started learning more about myself and the things I cared about. She actually glowed in the dark, and was representative of "a light in the dark", a guide and a support for those who needed one.
And then my latest one, Daylight Glisten, who to be honest became a thing once I realized that what I'd chosen for myself was not sustainable, that I needed to take care of myself and not just take care of others.
And to be honest I feel like another persona still is on the horizon. Like each different persona represents exploring and expressing different parts of myself, so when I move on to something new my persona changes too. My personas end up being pretty specific because of that, which I think is why they don't last for more than a few years even if I still really like them. They end up marking off phases of my life rather than being simply me, I definitely find merit in that but it's also kinda frustrating.