Bastien Guerry has a longish post on how he uses Org mode for task management. If you’ve been around Org mode for any amount of time, Guerry will be familiar to you. He took over the maintainership of Org mode when Carsten Dominick decided he needed to get back to Astronomy, which is, after all, his profession. Since then, Guerry has stepped in when Org needed him and has continued to be a presence in the project.
His years of working on Org mode internals have given him a first rate understanding of how Org works and the best way to use it. Therefore his post on how he uses Org to manage his tasks is must reading for all Org users. Guerry will be the first to tell you that his system may not be what you need but his reasoning for why he made the choices he did is instructive for us all.
I don’t really use Org to manage my tasks to the extent that Guerry does. For me, my agenda is more of a display of my daily log although some tasks do find their way into my agenda. Regardless, I found his discussion of his organization of tags to be very helpful.
No matter how you use Org mode, you should take a look at Guerry’s post. He has a lot of good ideas that you may find useful.