We've all seen various time management schemes in which daily tasks are prioritized.
Most advocate the use of A, B, and C designations with "A's" being tasks that will be an embarrassment if left undone and then the other labels progressively dropping in importance.
Embarassment is not a bad standard, I suppose, but it is certainly not the only one and, as Stephen Covey has noted, sometimes greater attention should be given to those Not Urgent But Important tasks which may not mean much today but may make an enormous difference three or four years from now.
Some other ways to organize your day or week are less conventional. One approach is to focus on a particular theme - office organization, for example - and do things that advance that area. Another is to address commitments to people or institutions: "This morning will be limited to working on the Parks project and the afternoon will be dedicated to the Phillips account." Many of our greatest regrets in time management come when we have failed to keep commitments to others.
[One of the most common time management mistakes is using schedule books solely to chart meetings and not activities.]
The two key factors in any of these approaches involve deciding what is worthy of time and then focusing on the top two items. Ideally, you would focus solely on one priority but boredom and interruptions make it wise to have the top two in mind so if action on one is blocked, you can shift your attention to the other. Once one is completed, of course, a worthy replacement can be selected from the back bench.
In most cases, this will be done amid a certain amount of chaos. Indeed, the actual work is likely to be done in bursts and not in a continuous, organized, flow. Recognizing that hard truth acknowledges that all work days - except those of neurotics - have lag times and goof off points.
The challenge is to make sure that the "down times" don't predominate and that the "focus times" are given meaningful amounts of time and attention.