Be prepared to deal with a skunk.  Best way is to wrap your trap in cardboard or a tarp.  It will get chewed on and torn, so I like to use cardboard.  If you don't want to deal with a skunk, get your trap up off the ground.  Coons will climb and skunks do not.  I like to use vanilla wafers, coons love them and generally cats will leave it alone.  Marshmellows are great as well and have great eye appeals.  I also sometimes put some peanut butter or jelly on the vanilla wafers.