Awhile ago I went google searching for a list of idioms, and I came across the most refreshing website
IDIOMS BY KIDS
I work in an office where many of my co-workers have English as a second language and therefore the idioms I use during my day are completely baffling to them. A good example is the time I said, "Daniel, my hair is on fire" ~ he looked at my quizzically and so I asked, "don't you have a saying in Cantonese like that?" He remarked "We say, he has smoking head or something like that.
HOLD YOUR HORSES