I always introduce my self, talk a little small talk, name dropping can be good if you have names to drop and get right to the point. They usually know when an unfimilar vehicle pulls up that the guy is looking for info or selling something, either way they are gaurded and it is best to get right to the meat of why you are there. I also will never stop when a guy is busy or eating dinner. Offering to help is a good idea, I have informed a guy a fence is down or his cow is out,etc and then offered to help him as an icebreaker. This can work but to say I will help with chores may look like your desperate. It is ok to state your ethics if he cares to listen or seems leary, just don' t seem fake and cushy as your relationship with him is very infant. Once I obtain permission I always stop in for coffee/chat when in the area, drop off meat(finished product) even if I harvested it elsewhere & some places I bring a 40oz gift(catch my drift). The point is keep building on the relationship and don' t ever break the trust level. Be responsible, courteous, respectful, honest and grateful of his permission.

Good luck!

PS If he doesn' t grant you permission be nice and thank him for his time. Always say have a nice day[8D]