Need some fancy words

I'll be sitting a CAE exam this Friday and I'd enjoy learning some vocabulary I can use when doing it.

Some idiomatic expressions, collocations or just some fancy adjectives or adverbs that you think could be useful. Something that if the examiner saw would make them say wow.

There is an speaking part where it's mostly informal language that I'm going to use and a more formal writing part.

Thanks for your help.