My 0.02, Don't use chicken, use fish. I had a couple of traps in ganges on Wednesday, I loaded them up with everything out of my freezer, a salmon carcass(wired to the bottom of the trap will keep crabs interested in longer soaks, so you won't loose as many), a few pieces of Cod, scallops, prawns and chicken wings, when I came back 4 hours later, both traps had about a dozen KEEPER SIZED MALES, everything was gone, except for the chicken and prawns, they literally had 1 little mark, and that was all.
Also, Marinate your bait with Pro-cure, Smelly-Jelly, or other Sardine, herring, etc scents. even if you just toss them with some of that, it will bring crabs.
I use double braid nylon, not crab trap line, it's easier on the hands, I would get 75-100 ft of it, zap strap a couple of 1lb cannon balls to the bottom of your trap, and use a line weight, as shown, attach it as soon as the trap hits bottom. Use small Polyform buoys (scotchman) if you can, they are BY FAR the most visible.
Unless you want little annoying red rock crabs, set the traps in mud or sand. REMEMBER to let all females go, you can tell because they have a "mountain" instead of a "lighthouse" on their bottom side.