Listen to what the client is truly asking for.
Many times, it's not what they say, but how they say it that tells you the direction you need to go.
Look at what everyone has done in the category.
Visual research — see what's worked and what hasn't. Then, try to understand why a certain approach worked and use that success to springboard your efforts.
Learn from the success and failures of others.
The client isn't always right... and neither is the ad agency. "Experience" is that thing that keeps you from making the same mistake again.
Bring together the best talent to produce the concept in a modicum of time, at an affordable rate, and still exceed expectations.
Try to see things differently. A door in an antique shop is just a door unless you can imagine it turned sideways and see it as a beautiful headboard.
Let your freak flag fly....