The Cut: Between illustrated fashion personalities, photographs re-imagined or fashion shows drawn andpainted, New York Magazine's fashion blog really knows how to find and commission people who create some of the coolest fashion art. Search through the site for more.
Paper Fashion: I follow Paper Fashion on Instagram, and I love the beautiful embellished drawings that come up in my feed. Katie Rodgers is extremely talented and really has an eye for bringing out the subtleties.
Honestly WTF: One of my favorite blogs, they cover real art, which I almost always love, but also fashion art and illustration. They find people from all over the world and bring it to their great blog. It's led me down a lot of hours of rabbit holes.
Pinterest: My board titled "Create" logs all the artistic ideas I find on Pinterest and all around the Internet. It's not just fashion art, but there's a lot of fashion art in there, and each pin will lead to where I found the work if it wasn't from my Pinterest feed.
UPDATE: Honestly WTF highlighted Vogue's December cover spread which used inspiration from iconic art pieces for recreations featuring Jessica Chastain.