Even I Use MSPaint

I didn't have MSPaint growing up because mine was a Mac household. Plus, by the time I was drawing digitally, I had a wide array of apps to work with, but I've always had a respect for the use of a limited toolset in creating art. A professor of mine had a quote from Jean Cocteau on every syllabus of his, and I still love it. He said, "Film will only become an art when its materials are as inexpensive as pencil and paper."
Similarly, I used to use a 3D modeling program called Strata Base. The company is still around, but the exact freeware program is long since retired. On its user gallery, someone commented on an image made with the software, "It's not the tools, it's the talent." I don't know of a concrete origin for that quote, but it's effectively saying the same thing as Cocteau. 
It shouldn't surprise anyone that many talented artists out there have done some incredible things with MSPaint, which in no small part helped keep it from the brink of extinction. Recently and thanks to Vox, I came upon an artist named Pat Hines, who shared some of his tips and tricks, including the use of gradients. Making gradients is actually easy, but it may not be obvious to users of more ample drawing applications. 
Zenbrush, my personal favorite drawing app despite the likes of Procreate and Autodesk Sketchbook residing on my tablets, has many similar qualities to MSPaint in terms of having a limited toolset, so this is a little bit of a handshake between these two gateways.