What strategy do you follow for converting internal exceptions into user message?

Hi,

As the title says, what strategy do you follow for converting functional and technical exceptions arising from feature workflows in a web service into user friendly HTTP response and status code?

How does your minimal HTTP error response look like?

How do you map cross domain exceptions?

How do you determine HTTP status code for all possible business exceptions?

What design pattern do you use to catch exceptions and convert them into HTTP error responses?