Usually, unwanted paper makes a mess, so before organizing file it is feasible to trash out the unwanted papers.

Keep those paper in a separate folder of the file that is of a permanent use like insurance policy, paper regarding taxes, medical records, retirement and investment documents, etc.
Manilla folders come handy when it comes to organizing files
Organize the paper or bills according to dates
On regular basis look into the files to get rid of the bills or document, you might not need any longer
Correctly label each file and organize its alphabetical order, for instance, accounting file should be in a folder A likewise your utility bill should be in U folder.   _{Your Comment}