Omnifocus is my Photoshop level tool for to-do tracking.  I've used it for years and there are still features and ways of using it that I haven't explored.  I don't use it all the time.  I only feel the need to use it for major projects that are complex, longterm, high stakes, and require me to be the only one in control.

I've recently pulled this old reliable tool back out of applications-folder-obscurity and it's now living happily in my dock again after many years.  I've cleaned out some residual tasks from long ago, and am rebuilding it for exclusive use during my upcoming doctoral course work.  

One of the first things that my new university sent me was a personalized course schedule taking into account my transfer credits.  I used this as a checklist to allow me to start building a framework for everything that has to do with degree completion.  

It's easy to think of each semester as its own project, because the university schedule is so time bound.  All of my classes will finish around the same time each semester.  All book purchases happen around the same time before each semester.  

Eventually, I may create a folder to help hide future semester projects with current courses living as individual projects.  The beauty here is that I know that this structure in Omnifocus will change and adapt to my needs.  As information comes in about future tasks, it's all going in here.  There will be no forgetting.  There will be no overlooking.  Every time a professor mentions something that needs to be done, that directive or suggestion will be caught by this system for future review.