I normally keep list of doable actions in the Notes field of a Task. The Task header will normally read:
Current Action [Project Name]

and the Notes field would contain:

+ Done Item 1
+ Done Item 2
_______________
- Next Item 1
- Next Item 2

Now there appear to be larger, complex projects like preparing oneself to a Caribbean holiday! :) It requires more thorough planning. But the most important feature of a “complex” project is that there could be several doable items on it…

So I introduced the concept of Subprojects. A Subproject is a Project that is a part of other Project. Each Subproject would have just one Current Next Action. Subprojects would be referred from Notes field of main Project as Referral items.
It may look like:

- >> Buy Air Tickets [: Tickets]

Subprojects will have their own Current Next Actions in the lists, and will be advanced independently. When complete, a Subproject will be ticked off the list, and its Referral item will receive an update in status:

+ >> Buy Air Tickets [: Tickets]

DONE

This enables to track even complex projects like moving house or preparing to a holiday.

Higher-level planning (on Life objectives & Goals levels) still remains to be implemented. Sally McGhee’s approach is one of them, but I don’t think it’s a good idea to have “meaningful objective” intermixed in the same list… something doesn’t seem right here. Gotta try & see.