Never give advice unless asked. – Proverb

It is more easy to be wise for others than for ourselves. – François Duc de La Rochefoucauld

In giving advice seek to help, not to please, your friend. – Solon

The true secret of giving advice is, after you have honestly given it, to be perfectly indifferent whether it is taken or not, and never persist in trying to set people right. – Hannah Whitall Smith