GETTING PERMISSION TO METAL DETECT ON PRIVATE LAND, page 3
Illustrated Guide to Obtaining Permission from the Property Owner
11) Be honest, sincere and yourself. Give full answers to all questions, even the most ridiculous ones, without hesitation. Make sure you maintain an eye contact with the person during the entire conversation - this may be more effective than any BS you say.
12) Make your request for a permission to hunt and assure the owner that you would treat the property with full respect and not cause any harm or damage to it: you would NOT 1) make any fires, 2) leave holes uncovered, 3) leave any trash behind (make sure you remove and properly dispose of any junk that you find), and 4) tamper with signs, structures or equipment.
13) Assure the property owner that you would metal detect with caution and not put yourself in any danger. Print out in advance and bring with you a blank form to sign which includes both a Permission to hunt and a Liability Waiver of any legal actions that could be brought against the property owner in case you break your leg, arm or neck (when you fall into the uncovered old well, for example) on his/her property. You can open and download the Permission/Wavier form in PDF format (you need Adobe Reader to open and print out the file) HERE.
14) Offer the property owner a 50-50 split of whatever "big" treasure you might find. Even If the person does not care, be kind to show your finds at the end of your search and give a representative coin of the types you find that day to the land owner as a thank-you gesture for granting you a permission and giving you an opportunity to have some metal detecting fun at his/her land. This is especially important to do if you plan or might need to return to the hunt site for more detecting later.
15) Offer to help finding something of value the owner may have lost. This would definitely reinforce your sincerity. If you do find something valuable, please follow through with your offer to return it.
In most cases, getting a permission to hunt is easy and does not require too much effort, but sometimes a detectorist might face a tough case. The first "red flag" showing the land owner's reluctance in giving you a permission is a common phrase: "some guys already metal detected here before and dug up everything!" You might say that you have a better metal detector, and "there are always coins left at any site," or come up with better reasons why you should be given a chance.
If the property owner is still "drawing out more red flags" such as "my nephew (grandson, mother in law, grandpa, buddy Joe) is planning to metal detect here soon," "I added a foot of new soil to my back yard last year" or "my uncle Sam (father in law, niece, buddy Joe) is coming to set up a swimming pool this afternoon," you just say "No problem and thank you, Sir!" and leave. There is no reason to annoy the owner any further if he/she has already made up his/her mind and firmly tells you "No" in a polite form.