The one piece of work that has remained consistent through out my time using the piskel online tool for work, is the helmet/head sprite that I posted, Its stayed that way for two reasons.
A. I put the most work into it. Based it off of an IRL racing helmet, images of which I researched over either duckduckgo or google images, I can't say for sure which as I last tinkered with that phase about 1 whole year ago.
B. I've also been using it's framework as a basis for other similar designs and expectantly isn't very useful for designs that are helmet less. (not that I am good at drawing any kind of hair to begin with.
here's a link to the piece!
I will say one thing though, I've certainly hampered myself enough trying to figure out how to use it with some other concept artwork I've made, as the scale is very annoying, what being close to only 32 pixels.