Scout, find birds, find the fields they are using, find the flight paths they are using, find the area of the field they are using, find what time of the day they are using the field.
If you find answers to all the above you will have successful hunts. It may take hours and days to find the above answers but once you do you will know where and when to hunt.
While good advice in general - that's a futile effort the first 3-4 weeks of the season on any of the APH lands in the area.
IF (I refuse to) I were going to hunt any of the APH dove lands in Collin/Rockwall counties opening day - or the first few weeks - I wouldn't waste a bunch of time trying to scout for the best spot. Everyone knows about it. It's going to be very crowded. It's probably going to be very frustrating having ever public dove hunter in a 30 mile radius up your butt. The vast majority of these people dove hunt only and have zero respect for other hunters or for safety. Call it ignorance or call it [censored] - it is what it is.
If you take 2flyfish4's advice - and apply it at the end of September - you'll have some success and much more enjoyable time in the field because you're not dealing with every great white dove hunter from N Texas.