Project/Next Action Verbs - For project and next action lists, it can be helpful to think in terms of actions you can see completed. Here is a list to help you think about verbs to help you clarify next actions.
Next Actions: Building a Smarter To-Do List, Part Two - The second of Merlin Mann's posts on Next Action lists.
Next Actions: Building a Smarter To Do List - Merlin Mann's 43Folders, the site this link is taken from, is an excellent resource for productivity tips. This is the first of a two part post that discusses how to make a next action list that clarifies what must be done to complete a project.
Incompletion Trigger List - A trigger list helps to "trigger" your memory of tasks to complete. You can use them as part of of a routine review. This is the Getting Things Done trigger list, which includes two categories, personal and professional. The profession list is on the second page. You may find it incomplete for your purposes-- you may find it useful to develop trigger lists for your particular field of endeavor.