Dimitri Burakov is an incredibly talended LEGO renderer from Lithuania. He uses an array of programs to create anything from polished renders to professional instructions of LEGO models both official and fan-built.
I recently came across his works on Brickshelf and contacted him about cooperating on some projects. The results are amazing. Below is a beautiful rendering of my tripod mecha with sample instruction steps. In exchange, I shipped out a big package from S@H.
If you’re interested in having renderings and/or instructions done for your work by a professional, you can find Dimitri’s contact info at his Brickshelf gallery.