This time of year, most coyotes are paired up and mating. The last several ******* I have killed were in heat. Howling is a great call now! Coyotes are very territorial, and will come to run your butt out of their area.
Also, if it is like around here, a distress call of a rabbit will scare more coyotes away. Everyone and their brother has been out all winter blowing that sound, and the remaining coyotes are call shy to that. Try a deer distress with your voice. I hold my fingers on my nose while making a whaaaa, or baaaa. Throw in a couple coyote yelps, as if the coyote got kicked, add more deer bawls, and keep watching, they will come.
Also, while bowhunting coyotes, you may want a second person set-up downwind 50 yards or so. Most coyotes will circle, and you want someone there to take them out.
A decoy like a feather blowing in the wind can help. but I have found not needed. Cover scents are way over-rated. I tried skunk, and fox/coyote urine, and them coyotes smelled me right through that stuff at hundreds of yards away. Try to play the wind at all times.
Best of luck to you!
The best way to get good, is to keep after them and learn from mistakes. There are a few decent coyote calling videos out there. Randy Anderson has some good ones that should fit well for your area.