Endnote provides two hierarchical levels to organize your references: grop sets and groups.
I prefer not to have more than eg 20 references grouped together in one “place”/view not to get confused. Thus I would like to have at least one more level of hierarchy. Tagging references in the label-field is too cumbersome as a remedy as you can’t just right-cklick on selected references to select a tag from a predefined list - you have to move selected references to a separatefolder and then wade through the library menue …
What is your workflow? Do you maintain several libraries, one for each major (or minor) area of interest?
A related topic of ergonomics: is there a shortcut to close the edit-pane at the right side? It pops up by double-clicking on a reference, but how do I close it if I don’t want to use the mouse?