The free version of Autoptimize is incredibly robust and covers 90% of what most sites need for CSS and JS optimization.
That being said, for optimizing paper (or more generally, images) for use with Autoptimize Pro or similar plugins, here are some general guidelines: autoptimize pro nulled exclusive
If you're hesitant to use a nulled plugin, consider the following alternatives: The free version of Autoptimize is incredibly robust