Poverty is stranger to industry.
勤劳之人不受穷。

Practice makes perfect.
熟能生巧。

Out of sight, out of mind.
眼不见，心不烦。

One who has seen the ocean thinks nothing of mere rivers.
曾经沧海难为水。

One swallow does not make a summer.
一燕不成夏。

One is never too old to learn.
活到老，学到老。

No fire without smoke.
无风不起浪。

Never judge by appearances.
切莫以貌取人。

Never hit a man when he is down.
不要落井下石。

Mind acts upon mind.
心有灵犀一点通。