When I was younger I would get up on the roof of my parents' house and shoot(we grew up on a good size piece of property). For the last few years my Dad, Brothers and I have been shooting out of an elevated platform that we constructed. I think it is of little value to practice on the flat ground and when season starts to get up 18'-20' in a tree. Your sights will not be accurate because of the downward angle and your form will be cosiderably different. We built it out of wolmanized lumber and it is more like a deck in the sky than a treestand.It has railings and bow racks and a tube on a rope that we hoist our arrows up with. I'm sure that if you find a friend who is in construction that it should not be too difficult. Think along the lines of a freestanding scaffold. Use an aluminum ladder for access.