What do you think I could improve?
Lol, if you want a rating based on the best I've seen, every one of yours would be 4-5/10, but I try to limit judging based on the skill level in this site alone (almost everyrone's -including yours- style is the same, smudge in a direction, add sparkles and stars, maybe an overlay, then call it good). DeviantArt's signature section, and multiple forums dedicated to this have people way better than you and I.
But out of curiosity, what are the best you've seen? PM me with a reply if someones already rated below.
Also, sorry if I sound like an asshole