Call your prospective clients and leads back. You would be absolutely shocked how many of my clients came from other firms who just would not call them back, wouldn't give them the time of day.
I have a pretty full client roster, so sometimes I have to turn down work. I don't do it by just not answering phone calls or emails. I respond, let them know that with the time it would take to get their project done and done right, I simply don't have the manpower or time to work with them. THIS time. I then recommend another small firm, wish them luck, and tell them I'll be in touch down the road.
This simple act -- it's a 5-10 minute phone call, really -- is ignored by many, many people.
Social media/online content
Nobody puts Jay-bee in the corner.