旁敲侧击；拐弯抹角
beat about/around the bush
Why should you beat around the bush when asking for higher wages? You deserve more money.
　
茶杯里的风暴；茶壶里的风暴；小题大作；大惊小怪
a storm in a teacup; a tempest in a teapot
Although Mr. and Mrs. Wang had an argument last night, It was just a storm in a teacup.
　
害群之马(团体中的败类)
a/the bad/rotten apple; black sheep (如果是 "the black sheep of the family"，则意为「家庭中的不肖子」)
Most students in the class study hard but there are a few rotten apples.
There are quite a few black sheep in the Legislative Yuan.
　
酒肉朋友
a fair-weather friend
I cannot believe that John was a fair-weather friend of mine, because he has promised to help me whenever necessary.
　
借酒浇愁
drown one's sorrows
If I fail my examinations, I'll go and drown my sorrows.
　
骨瘦如柴(瘦得皮包骨)
(as) thin as a rake/lath/stick
He had been ill for several months, and looked as thin as a stick.
　
家丑外扬
wash one's dirty linen in public
Don't wash your dirty linen in public. (家丑不可外扬)
　
海底捞针
look/search/hunt for a needle in a haystack
It's pretty much like looking for a needle in a haystack because these fish are extremely hard to find.
　
差之毫厘，失之千里
A miss is as good as a mile
I've tried to reassure him that he only failed by three percent but the way he sees it, a miss is as good as a mile.
　
留得青山在，不怕没柴烧
while/where there's life there's hope
The company has survived previous recessions; while there's life there's hope.
　
破口大骂
swear like a trooper
"If you are going to swear like a trooper, I am going away."
　
乘人之危；落井下石
hit a man (or someone) when he's down
Never hit a man when he's down. He may get back up again.
　
栩栩如生；维妙维肖
to the life
She painted me to the life.
The portrait is drawn to the life.
　
唇枪舌剑
cut and thrust
There was a real cut and thrust between them about the game.
　
班门弄斧
teach one's grandmother to suck eggs
He is always telling the director how to run the business; that's like teaching his grandmother to suck eggs.
　
殊途同归；条条大路通罗马
all roads lead to Rome
Helen was criticizing the way Jill was planting the flowers. Jill said, never mind, Helen. All roads lead to Rome.
All roads lead to Rome. I believe we will find a way out.
　
挨家挨户
(from) door to door
He sells dusters (from) door to door.
　
胸怀大志； 抱负远大
hitch one's wagon to a star (or the stars)
Allen's hitching his wagon to a star--he plans to be an entrepreneur by age thirty.
　
臭气熏天
stink/smell to high heaven
That fish must be a couple of days old. It stinks to high heaven.
　
泰然自若
(as) cool as a cucumber
Despite the mishap Margaret was cool as a cucumber.