I created lists by categories of tasks, e.g. "administrative" or "management".

Each category contains tasks with priorities and due dates. But there are also priorities in the categories of tasks themselves.

Therefore, I put stars in front each categories : 1 star for the most important (* management), 2 stars for the second most important (** administrative), and so on (*** development)

And I start with the tasks with priority 1 from the most important category, then priorities 1 from the second category, and so on.

Proceeding like that, all the most important and urgent tasks are always done on time.