To be honest I think we are very lucky to be so lightly regulated around unlicensed (and even licensed) A/G airfields in the UK. It all relies on common sense/airmanship. But that in turn is heavily dependent on the standard of instruction in pilots' original training, and in club check rides, the reval one hour with an instructor etc. I think instructors are generally very forgiving of bad habits or lack of knowledge shown during dual checks etc. Joining procedures and circuit flying are potentially the most hazardous bit of most PPL flying and I think it is incumbent on instructors to ensure that people are doing it safely and help them to do it better when they see poor procedures/knowledge.