I try to have a few days each week in which I'm free to get on with my work clearheadedly, without thinking about the task list. So, tuesday, wednesday, and friday are 'off days' from doing tasks. I have this smart list set up:

(due:tuesday or due:wednesday or due:friday) and priority:N

Every so often I go to that list, select them all, and keep pressing 'postpone' until the list is empty. Anything that really has to get done on an off day gets given a priority, so it doesn't get postponed.