Here is my method.
Every shop that I do has a paper worksheet created specifically for it. Each worksheet has pertinent data to the particular shop and any receipts received are stapled to them. Each worksheet has a space for the score or when it was approved. It also has a space for when payment was received and how much the payment was. The worksheets are filed in a folder for the month that they were done. Each monthly file folder is put into a box labeled for the year that they were done.
I keep those hard copy boxes for a minimum of about 3 years before disposing of them.
As for my photos of those shops, I keep them on my laptop filed by type of shop, city or town and by address of the shop. I keep them there until I do the same shop again. So, for instance, some shops may have photos dating back a few years. When I do the shop again, I review the photos and then send them to my Recycle Bin. They stay there until I decide to empty the bin onto a thumb drive. Similar to my hard copies, I delete them completely from the thumb drive after 3 or more years.
It's really not that hard once you set your mind to it.
Why do I do it? I've been audited by the IRS.