Just put some roosts around at different heights. I use tree branches, but it can be any wood. I also have a salad bar. You can use open bottom wood boxes of any size, make a lid of hardware cloth and wood trim, secure it to the bottom with hinges. Fill with dirt, then plant any kind of greens you like. It'll grow up through the hardware cloth, but the chickens won't be able to destroy the roots. That way they'll always have greens to eat. If you don't want to build the box, just use sweater boxes from the dollar store and cut out the top and bottom. I've heard some people mention hanging pie plates for them to peck at or building them swings, but I've never done either of those. I also have areas where they can hide, in case one of the other birds pick on them.
