How to create moving essays for IELTS

How do I impress my examiner on my essay? I am not a big fan of highfaluting words. I will rather use words that is cleverly concected to bring a clear meaning to my reader.

I have been reading wildly and I have noted the ones that have really caught my attention. Here is my list, would you mind adding more? thanks

1. boil
desperation boiled over earlier this week

2. speaks volumes
The fact that apple designed and manufactured its own processor specifically for the Ipad SPEAKS VOLUMES about the companys vitality.

3. Fireworks
Fireworks erupted between the defence and the prosecution panels

4. seismic shift

5. Moral compass

more ideas? thanks