back and forth = not to stay still, but to keep travelling between two places: "I'm so glad I'm moving. I was getting sick of going back and forth every day. Now my journey to work will be a lot quicker."

dribs and drabs = not a steady amount of something: "The marathon runners finished in dribs and drabs."

said and done = to have the final word on something: "When it's all said and done, the new reception area is going to be a credit to the company."

cat and mouse = doing something in the same way that a cat plays with a mouse: "The guerillas played a cat and mouse game with the much better-equipped army."

trial and error = to do something new by making experiments and occasionally failing: "The new computer system has been installed. But it's a bit trial and error at the moment - nobody really knows how to use it."

flesh and blood = your family: "I have to help him if I can - he's my flesh and blood."

down and out = someone who has no money at all who has to live on the street: "There are too many young down and outs in London."

by and large = generally: "By and large, our customers prefer good service to low prices."

And a further ten expressions:
Up and running = in operation: "The new company is now up and running."

Noughts and crosses = a game where you take it in turns to put your symbol (either a nought or a cross) into one of nine spaces. The idea is to have a row of either three noughts or three crosses, but your opponent tries to block you. The game looks like this:

O X O
X O X
X O X

Bring and buy = a fair where people try to raise money for a cause by bringing something that other people might want to buy: "I'm making a cake for the school's bring and buy next week."

Hide and seek = a children's game where one child hides and the others try to find him / her: "Someone's been playing hide and seek with the TV remote control again!"

Around and about = a vague phrase to avoid saying where you have been exactly: "Where have you been - I've been worried!"

"Oh, around and about, you know."

To and fro = another way of saying "back and forth": "I'm exhausted - I've been going to and fro all week!"

Over and out = something you say to show you have come to the end of your message: "The last thing they heard from the pilot was 'over and out'."

Done and dusted = properly finished: "Well, that's this project done and dusted. We need a holiday now."

Dead and buried = something that will not happen: "That idea is now dead and buried - the Executive Committee decided some time ago to go with another proposal."

Wine and dine = to entertain someone lavishly: "He's well-known for wining and dining his business partners."

Bread and butter = your main source of income, or the most important issue: "Health and education are the bread and butter issues facing the UK government."

Spick and span = very tidy and clean: "Her house is spick and span at all times."

Wheel and deal = to make deals when buying and selling things: "If you need a new car, try speaking to John. He's a bit of a wheeler and dealer!"