I went from only being able to draw 2D blueprint-style weapons or armor to only being able to draw slightly more detailed 2D blueprint-style weapons or armor.
In all seriousness though, my art has drastically improved. I wish I still had images of some of the stuff I drew when I was younger, but alas, I always drew in composition books, and they don't really maintain quality when they're in a stuffed schoolbag for 10 years. I do have a slightly more recent comparison, however:
This piece was drawn in a composition book over a year ago. Still much better than a year or two before, but since then I've improved the design.
As you can see, it's a bit cleaner, and also has better detail. Plus, instead of trading the Elda's mustache for buck teeth, I've now just made it look more like a gas mask or something.