I use Due days only if I have a commitment to finish the task before a certain date. In other words, if I don’t do it before the Due date, I’m in trouble. All other tasks are to be done as soon as possible, but preferable within a week’s time (I do a weekly review in which a pause or activate tasks when necessary).
Each morning I flag the tasks i wish to complete that day. I have created a special perspective showing me all flagged tasks together with the tasks due today so I now in which tasks to focus.