AOSP is a great start - but increasingly doesn't deliver all the functionality you'd expect in a phone OS. Even the mail client that was present in early AOSP is no longer there: You're expected to use the closed-source GMail app.

This talk explains shows how to get most Android functionality on AOSP without having to use closed source applications.

It covers integrating GMS-like services through microG and Open Source alternatives to applications typically preinstalled on Android phones, as well as tricks for better integration of alternatives.