Short answer: weekly review. This is your time to look back,look ahead and plan.
Originally Posted by Eternal Optimist
Longer answer: people are different, jobs are different and each project is different. Your GTD tools for calendar, lists and project support are probably not the same as mine. As you gain experience with your work and with particular types of projects, you will learn what is required. For most people, most projects don't require more than a desired outcome and at least one next action. For the more complicated projects, it all depends.
Suppose I am planning a wedding and writing a novel, both to be finished in time for the honeymoon a year from now. There's lots of information available on how to plan a wedding, and the critical early phase is choosing venues for wedding and reception. A novel, on the other hand, is likely to require a long middle phase of sustained writing. To produce a novel in one year probably requires writing at least one or two pages every day for most of a year. There's just no magic bullet that's going to fit every project. To know that you have projects, to review progress weekly and to keep moving forward with next actions are universal keys, though.