1. a spitting image - Looks identical
2. a crying shame - unjust/unfair
3. a nagging doubt - a feeling that something is wrong, but you don't know exactly what
4. a saving grace - one redeeming feature/ one (the only) good point in his/her/its favour
5. all the rage - very fashionable at the moment
6. a labor of love -hard work done not for financial or other material gain but simply because you enjoy doing it or sometimes because you feel it should be done.
7. with a vengeance - often 'came back with a vengence' For example, when an illness seems to go away for a time or starts to get better, but then returns much worse than it was before we say 'It came back with a vengence.'
8. swallow one's pride - used when you have to admit you were wrong or have to ask someone you don't like for a favour. It means you have to ignore the feeling of shame inside you and go ahead and apologise or ask as the case may be.
9. in good/bad faith - Usually this is 'in good faith' and it is used when you did something in the mistaken belief that you were doing the right thing at the time.
10. a vested interest - This means that someone has something to gain from a situation. For example, My colleague is thinking of leaving the company and asks me for advice. I know that if he leaves I will get his job which pays more than mine. I have a vested interest in him leaving the company so I am not the right person to ask for advice inthis situation.
Hope that helps