As a bookkeeper with about 30 clients, these are the essentials I use for keeping myself organized.
1. Slot-Shelving System
Think of the shelving system that hotels use for their guests to put messages and keys into. Each slot of mine is wider, of course. You can get these slot systems at Staples. I have a “slot” for each client, labelled. This will carry work that I’m holding from last time, for the next time I work on them. It also will include new stuff that I might get throughout the month via email/post but haven’t done yet. It’s stuff that can wait.
2. Accordion Files that I exchange with my clients
These are custom-labelled for their business. They fill it up during the month and bring it to me monthly (other clients are weekly). I have an identical accordion file here for them. When they bring me the full one, I give them an empty one. So they always have a place to put their paperwork. I keep my new accordion files on a special shelf location (not my slots, because they’re too small) and they are held there until I work on them.