That could be different at every set. First if you are hunting where there is a decent population of coyotes we have learned to make fox sets longer using very low volume on the calls. Remember a fox can hear a mouse under 2 feet of snow. There was a video on Youtube of this. Too loud of a rabbit or bird call may have a red thinking old Wiley coyote got himself a rabbit and I'm next. Also lights, i use as dim as possible. A friend was out hunting with a buddy, we talked yesterday and seems he broke all the rules he taught me not to do. You want to call in a fox that is why it is called calling. Using a huge light seeing eyes at 200 yards and shooting is not calling as i reminded him. That would be getting there attention and shooting. Calling them is easy i use a shotgun most of the time a rifle works as well. A very dim headlamp and a medium red light attached under the shotgun barrel near the end. You cannot beat a headlamp spotting a field it keeps the light steadier and far less movement to be busted. Using a hand light did not work as well for us. First you may be 2 foot from your partner and see the eyes and he cannot see them. I'm in the west i give them 35 to 40 minutes but we use a calling system that brings in coyotes or fox. We use a bird sound low on a electric call for about 5 to 10 minutes. We break about a minute or 2 and use a rabbit still mind you on low. Note are low is you can not hear it at 50 yards my partner and i signal each other with our headlamp. Not many fox want to tangle with a 150 pound rabbit. We play the rabbit about the same duration of time then use a red fox bark. One or 2 times and wait. After we do not see anything we will howl a couple times on a howler. And wait about 10 minutes. The key is the setup,the setup, the setup and the way you use your light. You want to be able to spot the field without back lighting.