Know the technology behind messages
While the word technology may imply an online focus, I'm talking more to the mechanics of any given medium. It doesn't matter if it's TV or billboards. Learn as much as possible about the production process. It's expected that you'll know the various styles and tones of messages in your given area of expertise. But understanding the production process is where you can uncover new production capabilities. This could be a video processing technique, or a way to use Flash that hasn't yet been done.

I'm not saying you have to be an expert on the subject. In fact, you surely won't be. There are way too many specialists for that to happen. It's more about having a working familiarity with how things are done. Years ago, I asked one of the top interactive producers what I should be doing to know more about technology platforms. He said, "Read Slashdot." I replied that I had no idea what those guys are talking about. He said it doesn't matter. Scan the headlines, and you'll end up with a sense of what they're talking about and what the capabilities are. That can be enough to prompt a good idea.

Knowing the details of the industry you work in also demonstrates to clients that you've taken your thinking to a deeper level. This gives clients more confidence in pursuing your recommendations.