Set up a foreign company (LTD or LLC etc.) from Italy (legally)

I’m looking for an expert who can tell me all the nitty-gritty of the matter: I would like to open a company abroad (for taxes but also because I deal with adult content) but I’m Italian.
I want to do things legally especially in my country (Italy).
So I would like someone who can tell me perfectly
– how does it work
– what is best to do