OmniFocus knows three different types of Projects: Sequential Projects, Parallel Projects and Single Action Lists. You would typically think that most of the time you need sequential projects, but that is not really the case.
First of all most projects are often a mixture of things when it comes to Actions: Some need to happen one after the other while others can be taken on in no particular order. Luckily OmniFocus allows for these any of these scenarios.
Secondly you will encounter a lot of these one-off tasks that do not justify their own Project. Per Getting Things Done® definition these would be tasks that do not need more than two physical action steps to achieve the desired outcome. "Clean up downloads folder" or "Hang picture in office" would be good examples. While you could argue hanging the picture requires to finding a spot on the wall and getting nails from the basement first, I guess we can all agree that we’re not going to micromanage ourselves here.
Lastly you have stuff, not even concrete Actions, that you can or do not want to make a decision about just yet. Amongst those are simple reminders, ideas and triggers you’d like to keep somewhere to look at them at a later stage. The Getting Things Done® methodology refers to these kind of stuff as "Someday/Maybe" items and that is exactly what they are. You may consider “Learn a programming language” at some stage, there is a “Situation with Dave” which you do not want to deal with just now and “Cottage in the mountains” could be a nice idea for a vacation with your spouse. For those things you need simple "buckets" to toss them into so you could review them every now and then, e.g. every 4 weeks, and see if you want to take some of them on or simply remove them from the bucket since they are no longer relevant.
Single Action Lists in OmniFocus are the solution for these "bucket" scenarios, either for the one where you need to execute one-off tasks or where you just need a "themed bucket" to drop things into.
Your One-Off Tasks Bucket
You create a Single Action List in OmniFocus by either selecting "New Single Action List" from the + button at the bottom of the sidebar (make sure you are in a Project-based Perspective) or by just adding a normal Project via the the File menu or using ⇧⌘N.
I generally advice to only create one Single Action List for individual tasks you can and want to action in the near future. But I have also seen implementations where individuals had a Single Action List in each of their Folders or per Area of Responsibility, e.g. "Customers → Single Actions" or "Finance → Single Actions". From a simplicity point of view I believe this segmentation does not add a lot of clarity and hence has very little added value.
Create a Single Action List on the top-level of your OmniFocus Library. This will be used for all these one-off tasks you need to accomplish, independent to which aspect of your private or professional life they belong. Collect every actionable, one-off task in this single list!
In OmniFocus 1 you have been able to configure your standard Single Action List in the preferences. With OmniFocus 2 this option is gone, unfortunately. While I consider this a bug the only way to ensure Actions land in your Single Action List is to call it Miscellaneous as this is the Single Action List OmniFocus creates automatically if it needs a place for an Action without an assigned Project.
In OmniFocus preferences (Menu OmniFocus → Preferences or ⌘,) under the Organization-tab you can configure how OmniFocus deals with Inbox items when cleaning up. If you want to prevent it from automatically creating it's Miscellaneous list and filing Actions there make sure you use "Both a Project and a Context" here.
Routine Maintenance Tasks Buckets
There are a lot of repeating tasks that come on a regular basis. "Submitting expenses", "Fill timecard" or "Backup laptop" are typical examples. You could have these as repeating tasks in your "One-off tasks bucket", but to better manage these maintenance tasks and sustain some structure, I recommend to keep them in separate buckets inside a "Maintenance" or "House Keeping" folder. I have separate Single Action Lists for daily, weekly, monthly, quarterly and annual Maintenance tasks.
By separating these maintenance tasks, you have a couple of advantages next to a more sane structure:
- You can set different “Review” cycles for these buckets since while you need to perform a certain action every week you may only need to review the "Weekly Maintenance Tasks" every 6 months
- If changes to your routines are required, you have a single place to accommodate the new circumstances
However, for larger reoccurring maintenance activities like the "Weekly Review", I suggest using individual, repeating sequential or parallel Projects.
Themed Someday/Maybe Buckets
This is my largest collection of Single Action Lists in OmniFocus and one of the most helpful ones as well. Particular in the Someday/Maybe domain, I believe many have not found working solutions yet. This one might just be it.
The most important aspect is to create Single Action Lists and put them "On Hold" in the OmniFocus Inspector (Menu → View → Show Inspector or ⌥⌘I). This will make them truly "Someday/Maybe" since things dropped here do not appear in any actionable view or Perspective in OmniFocus.
By definition things you drop into these Someday/Maybe buckets do not need to have actionable characteristics. In David Allen’s words it would be anything that has your attention, but on which you can or do not want take a decision or define a concrete Action.
Someday/Maybe lists can become very cluttered and it is easy to get numb at them once they get too long and badly maintained or reviewed. One way to prevent this is to implemented a few different "themed" lists (or "buckets"), e.g.:
- Read/Watch/Listen — Books, magazine or online articles you’d like to read when you have time, movies you want to remember next time you buy Blue-Rays or browse online rental catalogues, podcasts or audio books you could load for the next long travel
- Vacation/Trips — Ideas for where you and your spouse or your family could go to for the next vacation or free weekend
- Ideas for Kids — So you have the kids this Thursday afternoon and need an idea for a fun thing to do? Collect these ideas as you get or learn about them and have them ready when you need them
- Gift Ideas — What to buy for the husband's birthday? Which wine did uncle Steve like? Christmas presents for the kids? Note your ideas here and have them handy when events come up (which should be detected as part of your Weekly Review)
- Great Ideas — A bucket for the crazy ideas and dreams you have like "Boat trip on the Amazon river" or "Develop an ERP system in Rails"
- Learning & Development — Things you like to learn someday, be it painting, another language or presentation skills
- Wish List — All of those gadgets and things you like to buy, but you are not quite sure if you really want or even need them; Also a handy list to give people hints when your birthday is coming up
- Ideas for Friends & Parties — How about a Halloween Party this year or visiting Sue and Michael for a weekend someday?
- Around the house — There is always something you could redecorate or change around the house and in the garden
- Ideas for Blog Posts — Whether you are running a blog, write novels or paint pictures: Have a list to capture your inspirations
- Next time in… — Keep a bucket for things to do, restaurants to eat in, shops to visit or people to meet for your most common travel destinations
- Various — Well, the bucket that fits everything that does not fit elsewhere
Those "themed buckets" will represent the core of your Someday/Maybe implementation in OmniFocus. Have more or less buckets as it suits you. Just make sure they are all set to "On Hold" and you assign useful review cycles to them. Some of my Someday/Maybe buckets I review as often as every two weeks, others will only be touched every 3 months.
A Word About Parallel Projects vs. Single Action Lists
You could say parallel Projects and Single Action Lists are effectively the same and you are right with a few exceptions: A different icon and that all Actions in a Single Action List are considered "Next Actions" (i.e. "available") where in Parallel Projects only the first Action is consider available by OmniFocus’ Perspective filters.
The different icon remains quite significant difference since it helps you to visually differentiate real projects from simple ‘buckets’.
Single Action Lists in OmniFocus are a great tool to manage "buckets" of (partly) unrelated Actions or "stuff". You should collect all one-off tasks in an active Single Action List and reoccurring house keeping tasks in active Single Action Lists which collect all tasks that occur with at a similar cadence. Putting Single Action Lists in "On Hold"-status allows you to create "themed buckets" for Actions, ideas or simply things you can or do not want to decide about just yet, i.e. the classical Someday/Maybe items in the Getting Things Done® methodology.