The instagram account for Maude White whose delicate work is an inspiration. Her ability to work with shadows and positive space is truly fantastic. Her work is sold by this gallery.
A design student with some truly interesting pieces. A very visual blogger.
I have no formal training in graphic design of any kind. But using Chris Spooner's tutorials gave me a lot of very interesting basic knowledge about using Adobe Illustrator (though I use Inkscape, they're very similar, but Inkscape is free!).