Like I have said a number of times in here, Tuna in juice- add the can and all, just zip the lid off - that is a sure 98% successful catch.
For Cats, use sardines, just lift the lid off and set it in the trap.
If you have a trap with two ends of entrance, lock down the one where you set the bait. Be sure to secure the trap, rock, cement block on the top of the trap.
Coons have a habit of flipping the traps over and that is when the locks can slip.
Also when trapping coons, cats etc, keep in mind that you may want to put boards up about 1 1/2 feet, I used that cheap white garden wire people put up around their flower beds...This keeps the skunks out as they love a free dinner also.
Good luck!