I have always used Excel and my own version of a Kanban board.
Every year in January I say "This is the year I'm going to switch to an official database like Access".
I play around with it until the first returns show up, and then realize it's a waste of time. Spreadsheet have become much more versatile, and can be used as a database to find, sort and filter.
The Excel spreadsheet is my permanent record, and it lists not only the date of each processing step, but the prep fees, tel number, email, address etc. and any client notes that carry over year to year. When a client calls I quickly review their notes so I can ask not only tax questions but friendly icebreaker questions like how their new puppy is doing, if their mother is still in chemo, or if they got to use their boat at all last year.
They are always amazed that I remember stuff like that, and I just tell them it is because they are my favorite client.
When I finish a client I hide their row, so I only see the open returns. I print off a copy every morning, but things get overlooked on an eight page spreadsheet.
The white board is much easier to visualize, but of course it is temporary.
I put each clients name on a magnetic colored label; 2x4 for small returns or 4x4 for business and large personal returns, add the date received, and put it on the "received" column of my white board, and move it along as the return is processed.
The goal in my office is to "Get them off the board", meaning they are completely done, filed and accepted. We do a quick cheer every time I take one off.
I have a curtain that I use to cover it up when clients drop by.