Do as you would be done by.
己所不欲，勿施于人。
Doing is better than saying.
与其挂在嘴上，不如落实在行动上。
Do it now.
机不可失，时不再来。
Do nothing by halves.
凡事不可半途而废。
Don't claim to know what you don't know.
不要不懂装懂。
Don't have too many irons in the fire.
不要揽事过多。
Don't make a mountain out of a molehill.
不要小题大做。
Don't put off till tomorrow what should be done today.
今日事，今日毕。
Don't put the cart before the horse.
不要本末倒置。
Don't trouble trouble until trouble troubles you.
不要自找麻烦。
Don't try to teach your grandmother to suck eggs.
不要班门弄斧。
Do well and have well.
善有善报。
Each bird love to hear himself sing.
孤芳自赏。
Early to bed and early to rise makes a man healthy, wealthy and wise.
早睡早起身体好。
Confidence in yourself is the first step on the road to success.
自信是走向成功的第一步。
Constant dripping wears away a stone.
水滴石穿，绳锯木断。
Content is better than riches.
知足者常乐。
Count one's chickens before they are hatched.
蛋未孵先数雏。
Courtesy on one side only lasts not long.
来而不往非礼也。
Creep before you walk.
循序渐进。
Cry for the moon.
海底捞月。
Custom is a second nature.
习惯是后天养成的。
Custom makes all things easy.
有个好习惯，事事皆不难。
Diamond cuts diamond.
强中自有强中手。
Do as the Romans do.
入乡随俗。