I wonder what usually travels if one travels with a burner phone (a phone obviously barely previously used) to the US, or in other places where one would not wa

I wonder what usually travels if one travels with a burner phone (a phone obviously barely previously used) to the US, or in other places where one would not want to risk their phone getting confiscated. Is there any experience on that? Should one try to build some plausible deniability on that (eg use lightly a phone for a while for it to at least appear used)?