Makefile for a custom port

Hello,
I'm trying to make a port
This program has dependencies with Go to name one.
How should I indicate this dependency in the Makefile ?

Should I use BUILD_DEPENDS = or LIB_DEPENDS =Go is used to build my program but also to use it thereafter.
Should I use WANTLIB += ?

Also what is the right way to make an Openbsd package ?I read that in a port tutorial that the right way is to make the port and during that process the make package will do that.
Thank you