The real thing ended up remarkably like the digital plan. I'm impressed, and for that I have to thank Patrick, who made this plan into a reality.
Step 1: The Plan
The nice thing about having a plan is it kind of allows you to measure twice and cut once (though you should also still measure twice and cut once...). Here we used google sketchup, which is a really nice and simple free product. Patrick did a great job getting the plan just right.
Creating a detailed plan also helps you conserve your resources and use only as much material as you really need. We decided to make the long planter 12 feet long, 1 foot wide, and 18 inches deep. Short one in 5 x 1 x 18. The seats are 4 feet and 11 feet, and 15 inches deep.
Once you have the plan, it's time to get the materials...