We flew for many years at a grass airport in the country, no tower, and would alert anyone flying if an airplane was anywhere nearby. They would land if it looked like the full-size was fixin' to land. <div>I helped organize an impromptu club at (*gasp*) a tower-controlled field. Flew on the soccer field behind the tower, no taxiways or runways near. Needless to say, we stayed low but still had a ball. 
<div>We fly at a private field now and do the same. If one of the partners is out flying, as indicated by open hangar door and missing plane, we keep eyes and ears open. If its him, we land and critique his approach.  </div></div><div>It's all about respect, common sense and then having fun. </div>