Great question, Robert. I’ve struggled with this sort of situation myself as my OmniFocus library currently holds close to 800 tasks spread across 70 different projects. In the past, I frequently found that I had correctly captured a task and filed it away for later processing, but then I would never actually see the task or complete it as it was buried. This led me to question the reliability of my system and perform lots of work out of my inbox, which was the wrong approach to take.
I eventually solved this problem by realizing the importance of reviews, be them semi-daily, weekly, monthly, or yearly. In my case, I review almost all of the projects in both my work and personal life on a weekly basis. During each review (Monday mornings with a cup of hot cocoa), I get the chance to assess the state of every project individually and the tasks associated with them. I make sure that all of the tasks are still current, cleaning out anything that’s grown stale and adding new tasks that come to mind as I think about the project. Most importantly, each review gives me the chance to flag tasks that have become important since my last review as well as unflag tasks if they have lost importance. This review system ensures that all of my projects remain current and nothing is lost in the shuffle.
When the time comes to perform work, I can trust that all important tasks which should be worked on this week are flagged. This allows me to work down through the flagged tasks view executing the tasks which I am able to complete depending on my context. If I happen to complete all the flagged tasks which are available, that prompts me to perform a quick look through my active projects to flag another series of tasks to work on.
Due dates come into play as well. I too hate to assign a due date to a task which is not truly due on a specific day. Violating this rule makes it difficult to trust due dates and the system eventually breaks down. However, I still think it is valid to use a due date in many situations where the task is not actually due on that day. For example, in the case of getting information to my accountant, it may be reasonable to take a week or two to send that information over, but taking 3 weeks or longer would be rude as my accountant would begin wondering where the information is or might forget about the conversation that prompted the need for the information. In cases like these, I will set a due date according to my assessment of when it would become embarrassing to act on the task so late. When a task does have a due date, this makes it very easy to see the approaching due date during a review session and flag the task for action.
Another idea is a tickler file. While I don’t make much use of these myself, they can be handy. Ticklers are indicators which prompt you to check on a certain project or set of tasks in another location. Sundays are the day I clean my apartment, so I have a tickler on my calendar which prompts me to check my “Cleaning SAs” folder for all the tasks I entered during the week but didn’t consider important enough to flag. Another use case is for regular trips I take. I will create a new project for each new trip I take, but I also have a folder of single actions based on each location which collect ideas, locations to visit, items to bring, and other odds and ends. This means I will have a “Next Santa Barbara Trip” project in addition to a “Santa Barbara Spring 2018” project. When creating my Spring 2018 project, I will add a tickler action to check the Next Santa Barbara Trip project to see if there are any tasks I’d like to pull into the current trip.
Rereading David Allen’s Getting Things Done book was what made me realize the importance of reviews. Putting much more emphasis on performing complete, thorough reviews every week changed how I used OmniFocus and made me feel much more confident in my ability to rely on OmniFocus to get things done without forgetting about tasks or letting them rot in obscurity. I hope that you are able to find a solution that works for you so that your tasks no longer get lost or forgotten about. Good luck!
-Charles