This is something that I have not done, but when seen in an older thread (may be in the cover/structure archives) thought was a great idea.
With your post hole digger dig a hole and place a pipe vertical so it reaches a couple feet out of the water at the top. Then take cedar trees, run a cable through the big end, then put the cable over the pipe.
The reasoning is this. As cedar trees get a few years old, they loose much of their dense portion of the cover. So they need to be replaced or added to every five or so years. Your single trees will eventually just be stubs with only the largest branches left.
The pipe idea allows you to add to the tree pile a little each year or two. The trees will initially float on the surface but the cable will keep them in place till they water log and sink. Every year or two by boat add a tree or two. As the older trees have sunk to the bottom the newer trees will add dense cover to the upper areas of the water.
By having the pipe there you not only have the spot marked, but can easily add to the structure as needed over time.
I did not do that in my pond, but it seems like a great idea to do with a new pond where you can easily set up the pipes in a dry pond bottom. In a filled pond it might could be done, but would require driving a pipe in the bottom via a boat, which could be tricky.
As for placement, put it where you want to fish. Some within casting distance of any dock you plan to build is always good, as long as it will not interfere with any boat or swimming plans.
Snrub I'm with you. I know that trees and other affordable cover will not last too long. My plan is to drive metal tubing into the pond. A lot of them. Maybe 75 poles. That will last forever and I can go back at any time and drop tires over them, tie structure to them, and with the poles out of the water I'll know where they are. I'm trying to think long term and be able to replinish and add structure anytime I want, and know where it is. I tested it today and drove a pole 2' into the pond bottom and it's not going anywhere IMO. I think that's the way to go.
