Depends on where I am, and what time of year it is. Right now I use both hand calls, and my Foxpro, and do like Rick says, sound like two coyotes meeting each other for propagation purposes. I try to tell a story.
Female invitation from the Foxpro, wait a minute, then a male challenge from my howler, then a pissed off male challenge back from the Foxpro and so on. Then a "really" mad male, and maybe the female answers back. Then I shoot one (hopefully), then I run the pup in distress and shoot another one...or I pack up and move...I move about 10 times for each shot opportunity. My wife calls it "armed hiking" instead of hunting.