Your to-do list should only have the items that need to be there. To prioritise it, ask a series of questions about each task so you know whether to keep it on your list or trash it.
- Does this take me closer to my goal?
- Does this really matter to my boss?
- Does this make me money?
- Does this lighten my mental load?
- Does this have to be done today?
If you answer "no" to a task on all those questions, then drop it to the bottom of the list. The rest, order them by how many "yes" they score, with the most yes answers getting top spot. Of course, this depends on how big your to-do list is, use your judgement and make sure it's still useful.
5 Tips for Prioritizing Your Ever-Growing To-Do List [Fast Company]