x marks the spot: this is the place where you can find something.

A: Where are we supposed to dig?

B: Over there. X marks the spot.

you bet / you betcha: 1. yes; you’re right; absolutely. 2. you’re welcome (this expression has two different meanings depending on the situation).

A: Thanks for helping me.

B: You bet. (2)

* * * * * * * * * * * * * * * * *

A: Is Sarah really going to do what she said she would do?

B: You betcha she is. (1)

you bet your life: you’re correct (this expression is very similar to "you bet.")

A: Wow, she’s hot.*

B: You bet your life she is.

* hot: attractive; good-looking

you can lead a horse to water, but you can’t make him drink: you can’t force a person (or an animal) to do something.  

you can say that again: I agree with you; that’s correct.

A: That jet is moving really fast.

B: You can say that again.

you can’t make an omelet without breaking a few eggs: some things are going to go wrong, or mistakes will be made when you want to accomplish a goal.

you can’t take it with you: when you die, you can’t take your worldly possessions: money, jewelry, electronic stuff, etc.

Some people try to spend every last dime before they die because you can’t take it with you.

you can’t win them all: you can’t win every single time there’s a competition; you can’t always expect success.

Beverly was disappointed that she lost her tennis match, but you can’t win them all.

you get what you pay for: the amount of money that you pay for something often matches the thing or service that you receive.

A: This vacuum cleaner doesn’t work.

B: Well, you only paid about $30 for it. You get what you pay for.

you never can tell: it’s hard to predict the future; identifying something isn’t easy.

When you go to a casino, you never can tell if you’re going to be lucky and win a lot of money or be unlucky and lose a lot of money.

you’re telling me: I agree with you.

A: That’s a big fish!

B: You’re telling me!

your guess is as good as mine: I’m not sure; I don’t know.

A: What kind of a duck is that?

B: I don’t know. You’re guess is as good as mine.

you said it: you’re right; I agree.

A: He has a great hand!

B: You said it!

hand: cards (This is a word commonly used when playing poker. If you have a good hand, your cards are good.)

you scratch my back and I’ll scratch yours: if you help me, I’ll help you.

zero in on: to identify; to mark a point in the distance.

Once he zeroed in on the enemy, he fired his weapon.

zoom in on someone or something: get closer, usually with a camera; look over there and try to get closer.

Hey, zoom in on that girl in the blue shirt. She’s hot.