I haven't hunted public land for pheasants in nearly 20 years. I got sick of the crowds and trying to race to the spots to be the first one there, only to fight it after I got there. Hunting late season was nearly impossible after birds had been pressured for months. So I decided at one point that I was going to spend a lot of time scouting and knocking on doors instead, developing a network of landowners where I could hunt and generally avoid hunting pressure. Its paid of handsomely. I've developed about 12-15 really good spots all within about a 10 mile radius of each other and almost no one else hunts there.
I obtained permission at many of these spots when I was still in high school. By myself. With my own truck. Some said no. But many said yes, and generally speaking, once they say yes, they let you keep coming back year after year as long as you don't screw it up. I now do the same for spring turkey hunting every season. The one caveat is that most of this land is hunted during deer firearms season, so I cannot go in there until that is over in mid November. I am fine with that.
Every September or October, I spend basically a whole day driving around and asking people in person. If they aren't home, I have to go back. Its very time consuming but once the season is open, it pays off. I always offer them something in return. Most deny it. I offer vacuum sealed walleye filets, a cleaned pheasant, venison, or all three. Most people will not turn down walleye, but you would be surprised by how many people decline a pheasant or venison steaks.
I generally think most hunters are pretty lazy when it comes to trying to obtain permission on private land. Either that or they just don't have the time. Anyone could hunt all these spots I have hunted for years if they asked for permission. But no one else does. You have to also be willing to be denied.
I'm always looking for new spots to add too. Sometimes people move or the land gets altered and you lose a spot. Its gonna happen. But most of this private land generally stays pretty close to the same as it was 20 years ago. I generally think the best strategy is if you go solo or just with one other person. Don't show up with a group of 8 hunters and 5 dogs.