Suggestion #30: Many autistic children like facts and think very logically. Present to them the rules you would like them to follow accompanied with the facts on why it is important to follow those rules.
This always works wonders with my son. If he knows that something is a rule, he will want to follow it. It is up to us to clearly communicate what the rules are. Make them simple, easy to understand, and state them clearly without using hyperbole or exaggeration.
Also, I would recommend that they know what to do when they see someone else break a rule – that they come find an adult when one of the rules is not followed. Their passion for the rules can be high, and if they see someone else break a rule, they may feel obliged to enforce it. Give them an avenue to do so (coming to find the adult).