Was just updating my logbooks the other day, and came up with over 45 actual field landings in about 24 years of XC soaring (not counting grass airports or other official landing places). In all of that time, I've only had one even mildly annoyed guy, and it was because I landed in the half of a hay field that had been raked but not yet baled. He was actively working the half I landed in. After I got his son to help me move the glider to the side that had already been baled, I came back and started working with the son to load bales onto a cart. When he saw that, the farmer turned into my best friend. When it took a while for my crew to get there, he insisted on driving me down to the major intersection to wait for the trailer. Offered us dinner and drinks. You name it.

Other than that, I always follow the advice others have given. Thanks for your gorgeous field that saved my bacon. How's the crop this year. What's in all the fields. Etc.