Ok I'll try and break this down.
Yes big fields are always better to call but you can still hunt smaller lots. The same principles apply but when our viewing window is smaller these principles must be followed. First is the wind. Unlike deer hunting do not have the wind in your face you will get winded every time and not even know anything was there. Fox and yotes are going to try and cut down wind of your caller. So either have the wind at your back or at the very least across your face. Now if the wind is dead at your back make sure the area you are calling is working with the wind. What I mean by that is if it is a rectangle shapped field and you are sitting on info of the short sides make sure they wind if running directly down the field. You want the down wind side to be the biggest opening and have the best vision. If you hunt a cross win put the caller on the up wind side in the field and position yourself accordingly. Now the lights are personal preference but I prefer red over green as green has spooked more game for me. Also get in the habit of scanning with the bottom half of the light halo. Try not to put the center of the beam on the animal at anytime. I like to scan back and forth for the first 5 mins of calling just to make sure nothing is super close and it's running in. Then I will scan every other minute or so. ok lastly let's talk about yotes answering you. Different vocalizations mean different things. Barking is the only one I would be worried about bc that can sometimes mean you have been busted. Anything else you have I feel them out. And if you are using yote calls don't expect a yote to come charging in like you see on TV. 99% of the time they will post up 100 yards or more from where they heard your calls and check the wind. I have seen them sit and wait 45 mins before coming in. If you get answers stay with your calls, meaning do switch from howls and then all of a sudden go to dying rabbit. Stay with the yote vocals of some sort and try to tell a story. This is getting long but the last bit of advice is end your set with atleast 15 mins of silence. I can't tell you how many times those damn things wait till the caller goes off and 10 mins later come in to check it out. Best of luck out there