A tutorial I did for Digital Tutors just came the other week. I explain several techniques I use to quickly generate numerous environment thumbnails. I also share some of my work habits and thoughts to keep in mind for working in the industry.
Creative Environment Thumbnail Techniques
This is my first tutorial and boy did I learn a lot doing it. I know it's not free, wish it was, but working with them allowed me to set aside time to do this. Plus, they really helped me make a better tutorial than I probably could have on my own. I hope a lot of you find it helpful.