Create a component (like you would in Sketch) that lives on a dedicated "Components" page.

How it works:
1. Make a selection
2. Run the "Make Component" function in the plugin
3. A new Master Component will be created on the components page leaving an instance in place

You can even create multiple components from a selection all at once if you enable this option.

This plugin also has a secondary function called "Collect stray components". This function will find all master components outside of the dedicated components page, and move them to that page leaving an instance in place.