I have a two tiered nesting box with three holes on the bottom and three holes on top. The bottom holes are about two feet off the ground with a perch that sticks out for them to jump onto, then they step into the box. The upper boxes are about three feet off the ground with a perch out front for them to jump onto. Some people make planks that lead up to the high boxes and the chickens walk up the board to the boxes. If you do that, then you need to add raised strips every few inches so the chickens can get a grip and not slide down the board. I also put a shelf up on one wall with a crate screwed to the wall and shelf and within an hour of putting it up I had chickens laying in it! Hope this helps!
