The overemphasis in the GTD world of priorities being last place in the four-fold criteria for doing is, in my opinion, not going to help you get important things done. Merlin over on 43folders wrote a bit about why priorities are last place, and as sacrilegious as this may sound in the GTD world, I gotta say I don't agree with the idea that priorities are really that unimportant. Furthermore I think it's dangerous to your productivity to keep putting priorities at the bottom of your list of criteria.
First some background for those that may be unaware of the "Four-criteria model for choosing actions in the moment", they are, in order, as follows (p. 192 of GTD):
2. Time Available
3. Energy available
The crux of my argument is simply this: Your next actions, like it or not, are on a continuum of importance, making those at the top of the continuum much more important than others at the bottom. If you are constantly in the wrong context, constantly "don't have time", and constantly "don't have energy" (usually a guise for "just don't feel like it") to do next actions related the Lakein "A1" type projects, you may need to organizationally rethink your life at a higher level.
What do I mean by "higher level?" I mean higher than the runway. Yes, I'm using a DA'ism to emphasize the need for priorities. In fact, I would say that whole runway to 50,000 feet concept is precisely about priorities. Now, David of course advocates starting at the runway, which makes sense because you need to first feel like you have some control in day to day activities to clear your head for the higher altitudes. But for most of us, especially geeks, our runways are already well organized. In fact, we often have an elaborate collection, processing, and tracking system, as much as we can automated, gadgets for every step possible, and keyboard shortcuts to accompany all of it.
And that is where the danger lies. In the web GTD community (the only GTD community with which I am familiar) there is so much emphasis on "the cup", the system, the shortcuts, the runway, that when it comes time to doing, it's easy to think that quickly taking care of online bills, re-organizing your shopping list, typing up that blog post you've been meaning to write, or google-mapping the nearest oil change place and checking off any of these actions means your really getting things done. Sure, if you do any medium or low priority task you got something done. You certainly checked off an item from your list and that made you feel good. But the uncomfortable question of "is making sure I don't miss any item on my grocery list every time I got to the store really on my 20,000 ft and above list?" To each his own: If your larger life goals are to be the quickest email-processor, bill-payer, and errand-completer that your friends and family have ever known, then by all means make sure those tasks are completed with the utmost efficiency. But if those are not your main priorities, maybe you can let them slide in place of that large, nasty, 2 or more hour long, thinking-intensive, emotionally heavy, self-worth questioning task that does, whether you like it or not, have more priority than 90% of tasks on your next actions list.
But what about the four-criteria? I think you should have the discipline to make the four criteria work for you rather than being controlled by them. When there are important, high priority, next actions that are key steps in achieving your 10,000, 20,000, 30,000, 40,000 ft and above goals, you simply cannot let the four criteria get in the way. You need to use the four criteria as a checklist of things that need to be in place in order to complete your high priority items. What do I mean?
- I mean get in the right context. If you are constantly talking to colleagues and coworkers and checking off those agenda items, constantly driving around and checking off errands, constantly on the phone and checking off those items, but never at your desk to tackle the big action, you simply have to rework your allocation of time. I firmly believe there is no secret to this besides discipline: stop talking to other people, stop driving around making sure you pick up the nails from the hardware store and the butter at the grocery store in one trip, turn off the phone, and get to your desk.
- I mean find the time. No matter how many books you read and how many time-management catch phrases you can spout off, you still have 24 hours in every day like the rest of us. We are all busy and all wish we had more. We don't. The people that are really getting things done are the ones that are allocating these hours to those tasks that they feel are most important and will get them to their goals faster. For grad students, these tasks should be obvious.
- I mean find the energy. It's easy to get to work and check off 15 medium to low priority next actions throughout the morning and afternoon only to find yourself alone with the large monster task that you really should have been doing all along at 4pm when you have no energy and maybe not enough time left. Then what happens? Well you clearly don't have the energy: "I need to be 7.0 or higher for this and I've really crept down to about 6.9 right now, so I'll have to pass." So you end up doing more low priority tasks. Know when you have the energy to tackle the high priority items and do everything possible to make sure that time is free. If you never feel like you have enough energy for the high priority items, there are larger issues you need to tackle, perhaps obligations you need to let go.
Below is a screenshot of my outlook task list, organized by context, but with a "Laiken" field where I can mark a1 and have those tasks highlighted red (thanks to GTDWannabe for the privacy blurring idea).