Travelling to the US - precautions?

Hi all,

I am travelling soon to the US, for my vocation and as a long-time private person I will be taking some steps to maintain my privacy as I enter the country.

As this is an interesting area of the topic, I have decided to throw the question open to all of you.

What precautions (IT, physical, mental, otherwise) do you undertake when travelling internationally?

M.