Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.
Use rectangles to create a zig-zag plot: A series of rectangular lawns or any other ground cover or paving of your choosing - pebbles, decking - are laid at right angles to each other. They traverse the garden, giving strong direction. By Diarmuid Gavin.