Invest in some good fencing, I am told by my 40 acre owning friend - people seem to feel entitled to come on to open property for some reason.
Having grown up in the middle of nowhere being surrounded by open property.....
I always felt comfortable using it - especially for fishing. But I always asked the landowner for permission, first.
Asking permission was fine by me. Mrs Frost made great cookies, and she always had a jar full of them. :-)