Hello, sorry i don't know what phone guide you're referring to ("privacy" and "phone" in the same sentence sound really weird to me), but there's plenty of resources for "opsec"/"infosec" in a selfhosted context.

Here is a nice list of gamified challenges to reach. In addition, you may want to ensure you have Full Disk Encryption on your server (huge tradeoff: can't restart the server without entering your passphrase). Riseup also has tons of cool resources in their docs.

Like you admitted yourself, security and privacy are not the same. Running your own selfhosted services will probably leak more metadata than using shared services. For your personal conversations and your friends, it's a good approach. To organize political agitation against your nefarious nation-state, it's probably a risky strategy: breaking into your home to backdoor your server is easier and more discreet than to do the same for a shared host like riseup.

If you would like to give more specific about what kind of info you're looking for then maybe we can provide more detailed answer. Like poVoq said, we are interested to publish more guides on joinjabber.Org (we just started that project) to answer common questions/concerns. We have a draft FAQ (not merged on the website yet) about security concerns, please let me know if it's informative to you or if you have more questions.