Good advice all here and you would be well advised explore all the suggestions. I’m certainly no pro, but one of the challenges I have managed to make easier is purchasing a GPS Hunting App.
http://www.huntinggpsmaps.com. Having my whole state mapped with owners names, true borders of the properties both public and private and helpful overlays of other installed maps and data right at my finger tips on my handheld GPS. It’s not always perfectly up-to-date, but just the other day, I looked up an urban property of 9.5 acres just ½ mile from my house. The App gave the name of the owner and the border outline. Who knew this beautiful woodlot was that large just viewed from the road and with a quick Google search theowners name, I found their phone number and rang them up. 15 Min later I was able to meet with them in person and get permission in writing, albeit, written permission wasn't required in this circumstance. Very, very nice folks and I feel so privileged to find perfection so close to home right in town. My first hunt there was set up in a Caldwell chair pod very nearby their house, and within about an hour, the owner came out with small plate of cookies and wanted me to let him know when I was leaving because he and his wife wanted to be etxra quiet while I was hunting squirrels.
Can you believe that? Didn't get much hunting done but we had the nicest chat which was just fine by me. You can't put a price on a good rapport and he kindly invited me to their next weenie roast with family and friends. Sadly, the place is up for sale so I may not have privileges too long there, but I have made some nice new friends regardless.
I try to put myself in the shoes of the property owner. Personally, I HATE folks, even family members stopping by my place unannounced! I like to have my place presentalble for visitors and I’m not always fully dressed and/or just busy with other things, so a phone call, text or email ahead of time is always so appreciated. The hunting App gives me a real shot at finding property owners contact information so I don’t have to needlessly disturb them by just showing up at their door. Property lines are rarely obvious but with the GPS and the hunt App, I don’t have to wonder if I am encroaching illegally on someone else’s domain. Ideally it also helps to have adjacent owners permission in case game does a death dance right over the property line. In my state it's a illegal to retrieve your kill, or dispatch further those rare not so clean kills without that owner's permission.
As Ted wisely suggests, bring along your equipment and offer to show them. Folks often find the technology and weaponry fascinating. Dress halfway presentable and if you’re sporting those God awful tatoos and piercings, don’t have them on display. I know it’s hunting, but avoid showing up in vehicle that looks like you’ve been living in it for months on end. I like to stress safety and quietness of our shooting platforms right off the bat, answer all their questions and be ready with your own in learning exactly what they are comfortable with you doing there with all the when, where and hows clearly established in advance. I like including these on the form I use. Make sure you at least exchange phone numbers. If they don’t wish a courtesy call in advance that’s fine, but I often have few questions that arise from time to time that I feel need some clarification and folks generally appreciate your conscientiousness and being able to get a hold of you as well.
Good luck!
Rock