There's a lot of "Feel" that goes into calling. Comes with experience. Doesn't hurt to start low volume. But never feel it's a negative to get loud. Distress or vocals. More than once I have seen coyotes stick their nose right into a FoxPro caller on max volume!
Sounds like kittens an dothe domestics can work, but I honestly don't use them often. Lamb sounds have been money around sheep farms that I hunt. Anything can work, and it's never wrong to try even the most ridiculous sounds! If nothing else is producing, I will try anything that is out of the norm to trigger.
Moving around is a key tactic. if you call from the same spot time and time again, you're probably getting patterned by the coyotes. Especially if they've mead you before. If you get coyotes to respond and they won't commit, if possible, move closer and call from a different position. get in their bubble and often they will show themselves
Frequency... If I call a spot and don't get a response or showing, I am more likely to call that spot again without a long wait. If I get a response with no showing I will give it a bit before trying again. At least a week or maybe n more depending on pressure. If I can setup on the same coyotes from a different position completely, I will shorten the time if conditions permit. If I know I have been busted, it will be two, three or maybe four weeks before I try again on those coyotes. And from a completely different calling position.
Howls... I usually star out with a lone howl. Followed a minute or two later with a pair howl. if no response, depending o time of year I might go into some whimpers, a fight, or pup distress. a lot depends on where in the life cycle of the coyotes I'm calling to are. Here in NY we can't hunt them for half the year. We start in October so we're calling to young of the year and family groups early season. We end at the tail end of the breeding season in March. Not sure if VA has year round hunting, but I again say listen to the podcasts from FoxPro to get an idea of sequences by the calendar.
Good luck!