You cannot get everything done. Things will be left undone.
Therefore, be intentional about that. If things are going to be left undone, be sure that it is the right things that are left undone.
How do you do that? It’s one of the reasons you should have a list of goals, projects, and actions that represent a complete inventory of your work. By seeing everything that you have to do, you can identify more easily — in light of the big picture — what to delegate and what to just plain get rid of.