Assume everyone is stupid, lazy and possibly insane, including you
I don't think this attitude is helpful - it's going to leak out in your interactions and poison relationships.<p>You do need to consider the context and background of a person before you can properly understand or trust their opinions and advice.  For example, a physicist may be ignorant of how car engines actually work; a mechanic may be ignorant of some of the underlying physics.  You really need to get to know people and build a long term relationship to understand if their opinions on a topic are useful and informed.<p>I don't think there is a simple rule to working with other people - you just need to build a wide body of experiences yourself, and beware of relationships that grow too quickly or where the other person appears to have a hidden agenda.