Do you assume that a person is good until/unless the other person has given you reason to believe that he/she is not deserving of the trust/friendship?
OR
Do you wait for someone to earn your trust before offering your trust/friendship?
Well to me depends on personality. Don't to about anyone..but i usually have strong intuition Allah ka shukr hai when comes to trusting people around me. Though, i assume that everyone is nice in general but....i have to get to know person before trusting with my personal life.
I trust in the fact that sooner or later my trust will be broken by someone or another so trusting in a person who turns out to be untrustworthy makes me distrustful of myself