a couple years ago before my family owned land we stopped by an old farm house where we always saw people sitting outside, went up introduced ourselves and simply told them what we were looking for.
The Farmer was willing to allow us to use his land, he was very specific about what part of his land and when. We shot there for like 30 minutes sighting in muzzleloaders and picked up our mess and anything other trash we saw, made it nicer than when we got there.
about a month later after we hunted, we brought them deer sausage and a home made pie to thank them.
The invitation was extended after that.
Also, we only own 11 acres of timber but have permission to hunt hundreds of acres because we very politely asked for permission. Some land owners only let us hunt Dec. some only late Muzzleloader, some archery only, but its still access to land. A phone call to make sure they know when we'll be on property and what our vehicle looks like always goes a long ways too.
Kids are good selling points, bring your kids or grandkids with you when you ask. Then bring them when you actually shoot (at least some of the time). Old farmers love a good family.