Old hive bodies are great. One deep is a nice size to lure a swarm. Old boxes have the right smell. That's probably my favorite swarm trap. I run all mediums but I get old deeps from people who are going to throw them away and I can put medium frames in them. At worst, if I'm slow getting them out, I can cut the comb off the bottom of the frames and tie that in but the rest is already in frames.