Typically you would start out with a interrogation howl (long single howl), follow it up with another possibly. Wait a couple of minutes then start with your prey distress calls. Call for a minute and wait 5, call again, wait 10...
That is pretty basic but you will after time find your own sequence that you are comfy with. It will change from time to time as you will find other ways to get their attention throughout the season.
Lately this has been my sequence but it will change with breeding season coming in a month or so. Remember, I have a FX3 and all these calls are at a push of a button.
Male interrogation call, wait 20 seconds...repeat. Female interrogation call wait 2 minutes. Serenade (one 45 second loop) wait 2 minutes. Usually I've had responses at the female Interrogation and definitely by the Serenade.
I then move to my prey distress....
I *was* doing well with Jack Rabbit distress. 30 to 45 second of that and wait 5 minutes, again...wait 10 again. If nothing has come in I'll hit the interrogation again. Often I'll then get an answer now. I'll then raise the stakes and try a different distress, possibly more aggressive.
I'll keep at it for 45 minutes if I've had responses close enough to come in. If they are far away I'll try and get closer to them. No answwers and I call it quits after 30 minmutes.
Don't be discouraged if nothing answers. Often they don't answer if they are close and some times they just keep quiet and work their way in.