Your blog should be based first on your ideas. They make you remarkable, and that's what makes your business viable. But if you always blog about theory, people are fair to question what happens when your ideas are tested in the real world. As a result, you should blog regularly about how those ideas actually work. There are two general categories of posts that "make it real": posts about getting it wrong, and posts about getting it right. Here are some samples from the Original Green Blog:
Getting it Wrong
1 Bryant Park and the LEED Problem
LEED for Homes Awards - or - How To Shoot Yourself in the Foot
the WalMart Sustainability Index
Getting it Right
The Chael-Dover Cottage - What the Original Green Looks Like
Original Green Places - South Main
Local Places - Aurea in San Francisco