[pjb]

This seems like the kind of business that could be modeled in OF but it may be worth experimenting with grouping Clients as Folders with job projects in Folders and alternatively grouping Tasks Types (Design, Construction, Yard work) as Folders with Folders for each client (there may be a folder for each client in each Task Type). Once you have all the jobs entered, you can experiment with moving them around various organizational hierarchies.

I'd start with a Folder for Work, a subfolder for "Web Site" and another for "Clients", another for "Payroll" and other subfolders for whatever other areas of responsibility you have. A Project would be the goal to accomplish, some of which will repeat (Mow this guy's lawn, file payroll this month) and other which won't (design that guy's retaining wall). While a Client can have their address as a default context, there will be some projects and actions in that folder which use other contexts, as you've mentioned--no harm in that.

Then you can use Context view to get a list of things for a construction guy to do or a focused Project view when it's time to sit down and do payroll.

Don't give up. Let the hierarchy grow out of how you actually work. It's takes a second to make a Project a Folder and another to change your mind if it's not working for you. You may well have hundreds of Clients folders and their addresses as Contexts, but isn't that what computers are for?