Be kind to others in what you do, don't haggle over every little thing.
Tips
history
From《孟子·公孙丑上》: 取诸人以为善,是与人为善者也。故君子莫大乎与人为善 — 'to take from others to do good is to do good with them; nothing in a gentleman is greater than this.' The original meaning is 'to join with others in doing good.'
usage
Modern sense ('be benevolent toward others') is broader than Mencius's original ('do good together with others'). Both senses survive; modern usage dominates everyday speech.