there is alot of different howls that coyotes use, and it is difficult for anyone to know all of the "coyote language", but what I do alot, this time of year, is set up. just as you would normally to call coyotes, do two or three long howls, if a coyote responds to you, imatate what he/she said, then wait about 3 to 5 minutes, it may show up without any other calling, if it doesn't go ahead and do some dying rabbit blues for 5 or 6 minutes, and if it still doesn't show up, you can either try to howl again or do a, what ya might call a "coyote gitting his a$$ whipped" call, and wait another 3 to 5 minutes. When howling, the action will generally be slower, in other words, the coyotes usually won't come in hard like they do to distress calls, so patience becomes a virtue when howling.Like coyote seeker said, most of the time they will not howl back at you when you do a lonesome howl, they will simply show up to see who the intruder is, and if they do respond with the short howl bark challenge, you need to challenge back right after they do it, this will sometimes bring them in also and it may take a few exchanges between you and the coyote.
This last weekend I howled in a coyote, from when I started calling to when my partner for the day shot and missed, it took nearly 45 minutes, and honestly the only reason I sat there that long is 'cause I saw him coming a half mile out there and it took him that long to cover the distance, and he/she never once made any sound.That's where I get spoiled, I can often see them way out there, and it helps to learn how to call them, 'cause I get to see how they react to the sounds that I make.Sorry this got long.GOOD LUCK!