yes, a vantage point is always nice. Try to get a tree climber and get up off the ground, you will see so much more than on the ground.

if you can't get one and must sit on the ground, use the wind to your advantage. have the wind in your face. complete camo from head to toe. be still. the smarter coyotes will try to wind you so try to sit with something at your back so they can't get around you, water or anything else that will deter them from winding you. set up so you are in the shade. They have crazy vision so you want to hide as well as possible. try to determine where you THINK they will respond to the call from and look to that direction and remember, coyotes are hesitant to come into open fields during daylight, watch the tree lines. A good trick is, the night before or a couple nights before, get out near that spot and howl. listen for their response and remember that area because that's where the most likely will come from when you hunt them.
If you do howl to locate at night, when you howl and if they howl back, they will move after the first response to find the source of the sound. so if you howl more than once and get responses from different areas, it is probably the same group.

If you hunt that area and shoot one or not, don't hunt it again for at least a week. In this part of the country we call more coyotes than we see BUT they see us so give them time to forget about you, your smell and your calls. Good luck