In person is your best bet. A letter is so easy to throw away, plus it is very impersonal. Meeting with the owner, talking to him face to face gives them the chance to see what kind of person they are thinking about allowing on their property. It also provides the land an opportunity to ask he questions he might have of you, as well as for you to ask them questions. One question you really should think about asking is if there is any work the land owner may have that you can help out with. After all, you are asking to hunt his property, which has a monetary value to it. If you don't believe, just look at the cost of leasing ground or going to an outfitter! If all else fails, you can always try to lease the ground, but remember to be very respectful, even if you given a huge no. He may change his mind, he always has buddies and they talk. You leave with giving him a bad impression; I promise you that bad impression, with your name, will be shared. Good luck and I hope you find a place to hang a stand.