Folders and tags answer different questions. A folder says where something belongs; a tag says what it relates to. Trouble begins when one system is expected to do both jobs.
Use folders for broad homes
Choose a small set of folders based on how you use information: current projects, reference material, personal records, and an archive. These categories should be stable enough that you rarely hesitate over them.
If a note could fit two folders, ask where you would look first. Put it there. Duplicating notes to satisfy a filing system usually creates more confusion than it removes.
Use tags for a few useful connections
Tags work well for themes that cross folder boundaries, such as a person, a topic, or a type of document. Start with a handful and add new ones only when an existing tag will not do.
Avoid tags that repeat the folder name or describe obvious facts. A tag should support a real search: “show all meeting notes for this project” or “find ideas I may use in a future essay.”
Let search do the rest
You do not need to classify every detail. Search can find names, phrases, and dates inside notes without any preparation. Too much structure makes capture slower and maintenance endless.
Review your folders and tags after using them for a month. Merge tags with the same meaning, remove unused ones, and rename anything ambiguous. A good system is not the one with the neatest diagram. It is the one that lets you put things away quickly and find them without remembering the rules.