[SpiralOcean]

Photoshop may be a bit exclusive, although there are plenty of users who use it. But even compared to iPhoto, MS Word, Excel, Numbers, Pages... all of those apps are much more wide open and in my opinion more complex for users. Even for a user to set up Mac mail is more complex than setting up OmniFocus.

The trick for most users is to 'get it'. Changing their view of what a task list is. Especially with outlining, creating children, and what that means.

I find the easiest way to explain how to use outlining is...
If you can't complete an action, what steps would it take to move that action forward toward completion. Create these as children. Then when you get to the first child action, ask the same question, if you can't complete it, what steps would it take to move that action toward completion. Those are children of that action.

If a user does this enough, at some point they will hit the actionable items that are doable.