I first came across Miroslav Petrov's work back when I did some character designs for Privateer Press a few years ago. He did the color illustrations of 2 of the designs I had the most fun working on. The art turned out great and I've been inspired by his work ever since.
These images are from 2011 and he's done a lot more great stuff in the meantime. You can check out on his blog: http://soulsart.org/ or his deviantart page: http://mikeypetrov.deviantart.com/
My concepts are posted BACK HERE
To get to the point: He's got a new art book coming out on IndieGoGo HERE
If concept design and all around cool art are your thing, be sure to check it out.
Best of luck Miro!