I do prefer to camp on community owned land rather than individual's land.
Much less of a personal trespass or insult.
The whole basis of assumed illegality is an assumption that the land owner doesnt want you there.
Other bits of land are there for public use and in the absence of any sign forbidding camping (of which there are plenty) you are merely using it in an unusual way.
My favourite is Church property because I know that they are claiming it is God's house (and they often have taps, benches and mown grass) and from everything I have read their God is supposed to like me (even though I dont believe in him).
If they throw me off it would re-affirm some of my views about hypercritical church goers, as it is I have actually been nicely received.
I also like village halls and their fields, I do my share in maintaining our local one and would not mind if I found a tent up there in a secluded corner early one morning. You have to leave such places very early as they are popular early morning toilet spots for dog owners.