Vous to Tu

I would continue to use "vous" until the person says you can "tutoyer" him/her. I find that the safest way to go .

that's not really important. Let me explain you...
in English "you" is used for everyone
But in French "toi" is used for the friends and for all people who are familiar.And "Vous" is a sign of politeness and the same time that's the plural of "toi".for example when you want talk to me and another person you say "Vous"

Yes thank you. I understand the rules - but Im not asking about the rules. Im asking about your definition of 'familiar'. If people do not take any offense to either vous or tu then my question becomes unimportant. So what Im trying to gauge is the point to make the change because, as Im well aware this sort of thing is non-existant in English. So its a bit confusing. One thing I certainly want to avoid is seeming to be too cold with people by always using vous or over 'familiar' with tu, when I move to a country.

If you would rather be on a more familiar footing, ask whether you may tutoyer. If you are worried about appearing too familiar, you have your answer and stick to the vous. ( A Belgian women who I had never met asked whether I would mind her calling me (tutoyer), I didn't even know what tutoyer meant at the time)