I'm curious how other GTDers list processes that are ongoing and repetitive, e.g. reviewing budget/expense reports from direct reports, brainstorming rainmaking (or in my case donor acquisition) processes, ongoing connections with stakeholders, etc.
Like Kelly said: if on specific dates, it goes on the calendar.
For all those things with repeated actions and/or non-fixed or ad-hoc deadlines, I have a project in OmniFocus. I have my projects arranged in Areas of Focus, so this permanent project will then be sitting on top in each area. I also use a little special character to flag it to myself as a permanent project. So for example in the area-folder "Financial" my first project is permanent and is called "✿Keep track of personal finances".
Only 3-4 of my Areas will have such a project. For the rest it works better with checklists that I review during my WR.