These short tutorials by lastsummer.de show us how to create custom packages on FreeBSD, as well as set up a package mirror.

Creating Custom Packages on FreeBSD

…we are going to cover how to build pkg(8) (pkgng) packages away from the FreeBSD ports tree. This is useful for external/private repositories (mostly bigger ones or generally fast-moving) or non-conventional ports like database content or even system updates. pkg(8) itself provides the essential pkg-create(8) tool, as well as pkg-query(8), which we will use to generate embedded dependencies.

Link: http://lastsummer.de/creating-custom-packages-on-freebsd/

Setting Up a Package Mirror on FreeBSD

…we’ll look briefly into how to setup a pkg(8) mirror on FreeBSD. Essentially, we’ll only need a bunch of binary packages for the mirror, pkg-create(8), a running HTTP server and a configuration file for the new mirror on your target system. You must know how to build packages for your target system — if that is the case you are ready to dive in.

Link: http://lastsummer.de/setting-up-a-package-mirror-on-freebsd/