Here’s an interesting thread The Freelancer system discussing this problem. Check out the video Johnny posted in response if you have time.
I have my own version of this problem. I won’t go into too much detail, but here’s some advice: forget about the SYS.AC.ID numbers. I’ve found using ‘YYYY-MM-DD’ is useful for titles, and I sort projects into folders by year (‘YYYY’).
Yes, that’s way too many folders to functionally manage.
It might help to take a step back and think about what it is you need to organize as a freelancer. Consider “How many clients do I expect to have each year?” and “How many ‘projects’ can I expect per client?”. You probably don’t need as many folders as you think.
At scale, a database becomes helpful. The website and workbook hint at using databases, but in this case, I would definitely consider using one to manage project and client metadata. A good database will provide more functionality than a folder structure can.