[arendtio]

In addition, you might want to add an entry to your system menu or place shortcut somewhere to start a new instance:

  /usr/bin/firefox -P my-profile --no-remote

[unqueued]

If you want more fine grained control, check out https://github.com/dyne/tinfoil

I actually have some scripts for managing not just profiles but extensions. Hopefully I can get it cleaned up in time to put on Github.