Something to keep in mind...there's a good reason why you probably shouldn't spend a lot of time listing out every Next Action for a project. Based on the outcome of one of your Next Actions, the whole plan can change.
Here's a recent example from my own stuff. A client asked me about adding a certain feature to a Web site we were building. This spawned a Next Action, "@Office: Research implications of feature X". It turned out that the feature would have required substantial architectural changes to the Web site. Next Action "@Call: Discuss implications of feature X with client." At that point, the client decided the feature wasn't important enough to spend the money on, and the project "Implement feature X for client's web site" was unceremoniously deleted from the project list.
What if I'd spent an hour at the outset of the project listing every Next Action it would have taken to implement feature X? All of that time would have been wasted generating Next Actions that never got acted upon. Or, what if my client had decided after the initial review that he wanted feature Y instead? The whole direction of the project might have changed. On the other hand, had the client decided after our phone call to move forward, I could have easily identified the Next Action at that point (probably "@Office: Outline database changes needed to support feature X") and moved the project forward.