First and foremost, be faithful to your superiors, keep all promises, refuse the friendship of all who are not like you; and if you have made a mistake, do not be afraid of admitting the fact and amending your ways.
I have always laid it down as a maxim -and found it justified by experience -that a man and a woman make far better friendships than can exist between two of the same sex -but then with the condition that they never have made or are to make love to each other.
It is lack of love for ourselves that inhibits our compassion toward others. If we make friends with ourselves, then there is no obstacle to opening our hearts and minds to others.
Almost every man we meet requires some civility; requires to be humored; - he has some fame, some talent, some whim of religion or philanthropy in his head that is not to be questioned, and which spoils all conversation with him. But a friend is a sane man who exercises not my ingenuity, but me.