I have been doing/thinking along these same lines. What I have come up with is pretty simple. I have pictures of my last 3 rock jobs and a 5,000 gallon pond we completed on a simple fold-in-thirds flyer. On the front I have my name, phone number, a pic of my equipment and myself. Inside are the jobs in progress and finished products. At the bottom inside at the end, "we specialize in quality product and timely service" and the phone number again.
You get the picture......
My best advertising is word of mouth, regardless of how much I advertise, you can't beat a satisfied customer. I always make sure to leave my customers a few brochures and extra business cards when we leave the job.