I have a bucket full of scents, lures, and, urines! That bucket of lures etc... is responsible for the taking of many coyotes, fox, and a few bobcats. Along with that bucket I also bring a box full of # 2 and 1.65 Briger 4 coil spring traps.
Scents, lures, and urines are great for trapping, but absolutely not necessary for calling.