Getting ready for taxes - boxes of paper everywhere

Going through getting my mom's office area ready for tax season I have determined that the only sane way to sort out the boxes of paperwork is to start with a pile of boxes on the bed marked for the different categories, and go through the boxes to be sorted dropping things in each of the boxes. When finished start with one of the now sorted boxes and resort it into being organized. Put that one away and start on the next box. It seems to be working so far.