When I ask for permission to hunt on someones land, I do two things right off the bat. I usually try to get permission to hunt areas that are bordering one another, so every once in a while I see the land owner taking a walk on their property. I am usually dressed in full camo just because I am either walking in or walking out of the woods from hunting (On the properties I do have permission to be on). The first thing I do is adress them by either Sir or Ma'am. This is a very important step in gaining their trust (as long as you dont mistake the ma'am or sir and call them by the wrong gender

). Then just strike up a conversation and ask them nicely. I guess you could call it sweet talkin, but if you just learn to show respect to them, they will usually allow you on their property. USUALLY. Sometimes there is just no compromising withpeople. I also will take a garbage bag out and pick up trash that I find while Im on their property. Just all the little things like that.
Theres nothing that works better then just showing respect to them and their land.