Welcome aboard! You will find a lot of good information in this forum. I would look through the various forum titles and read for a few days, there is great info here already posted. I myself prefer a pond of an irregular shape, though mine is not really irregular yet... that will change after the rainy season. A smooth bottom is not really the best, cut it up and use it as structure with channels and/or mounds. You don't need to go overboard with structure, like trees and rock pyramids, but it is good to have some, I think the ratio is no more than 20% of the surface, but don't quote me on that. Depths of more than 12' aren't normally necessary, but it is good to vary the depth with some ledges and shallower areas. Keep in mind to much shallow, or to shallow an area will more than likely promote weed growth. I try to keep at least 2' minimum depth, this seems to have helped keep the weeds to a minimum and also helps disadvantage the blue herons we have around here. I have some small trees around the pond, but I don't reccomend them in the damn as they can contribute to a leak problem down the road. I have a couple of pictures on my website, you can get there at the top of my post. Good luck and I hope this helps you out.