Federating your Plume blogs and accounts to other instances

Simply put, read the Distant interactions section of Plume's documentation. It'll be more up-to-date and more thorough than I am here though this is simpler.

Getting your posts over there

To federate your blogs from your instance to another, it's as simple as navigating to
<remote-instance.com>/~/BlogName@<local-instance.com>

To federate your whole account, it's just
<remote-instance.com>/@/UserName@<local-instance.com>

Getting their posts over here

To federate someone else's blog posts to your instance it's exactly the reverse of the above. This is also how you view a remote profile so you can subscribe to it.

Blogs: <local-instance.com>/~/BlogName@<remote-instance.com>
Accounts: <local-instance.com>/@/UserName@<remote-instance.com>