Connie and Teen, I used the same system when I was working, only it was huge since I had a separate file drawer for each month. I called it a "suspense file", but it was the same thing-- each month's drawer had all the projects that had deadlines in that month and they were filed in order of due date. Can't believe I never thought to do that for my home office.
I put reminders on my phone with alerts, but found that that didn't prevent me from leaving all the paperwork out as I was always afraid I'd forget where I'd put it otherwise (figuring out filing categories is not my strong point and I have to admit to being a bit lazy about creating new file folder categories anyway). The tickler file is really simple once you've got it set up and it means I don't have to make new categories for things that won't be saved after they're done. Things that will be saved already have general categories that they go into in another drawer of the filing cabinet.
Teen- I bet you're glad to get that spreadsheet done- they can be time consuming to set up, but once done, well worth it.
Rob