Filing. Keep it simple.

The retention and filing of some papers is necessary.
Ready access to important documents will make your life easier.

However, setting up multiple and exacting categories isn’t a good use of your time or energy.
Use broad  general categories, that make sense to you.
Group like items together.

When (and if) the time comes when you need to find a document, receipt, or
policy; spend time then looking through your folder.

By placing the most recent papers in the front of the folder, you will be creating a chronological record, which will also help you locate things in a timely manner.

Only keep those papers you can’t easily obtain a copy of in some other manner.

Business, professional or tax related papers may require a different set of considerations-speak with your accountant or bookkeeper.
But the day to day papers, paid bills, and receipts most likely can be filed directly into the recycle can or the shredder.

Most papers that get filed are never looked at again.
Really.

With filing, as with most things in your house:  Keep it Simple.