compiling for other architecture

Hi all,

I am currently working on an updated port of net/pjsip. I have a personal
use case building for the raspberry-pi, too. All the information that I
found so far seemed outdated. Many are talking about building a
cross-compiler. With clang that should not be necessary, right?

Can anyone point me to more recent information on how I can build for armv6
on a x86_64 machine?

greetings
Oliver

P.S.: I know how to build for different architectures. My questions are all
about the "dos and don'ts" and best practices when it comes to the FreeBSDs
ports system.