There is some of the best hunting land in the state right around the corner from my house, maybe 1/2 mile away. Every spring you'll see flocks of 20 birds or more right out by the road. Everybody in the area said it was a waste of time to ask because the owners are hunters.
I stopped in anyway and spent a little time making friends. Turns out they were trying to find access to the lake I live on, so they use my right of way to ice fish in the winter and I turkey hunt there the spring.
Couple things to remember. Anybody that we used to let hunt our farmland seems to turn into a fool. Ultimately, they'd run over crops, let the cattle out, or shoot up something.
Never dump garbage. If you see something, pick it up
Never leave gates open.
Do not trample crops.
Find out up front what the rules are about bringing other people. Unless you know someone very well, keep the property to yourself.
Never cross in the middle of a fence span.
Find out what they want you to hunt, and what's off limits (even if it's legal)
I'd offer to sign a liability waiver right up front.
Offer to share your take if the owner is so inclined.
Get them something nice or do something nice in return for their generosity. Remember, you are nothing but a potential liability and a problem waiting to happen.