Calculate usable time
Start with the working time left after meetings, travel, fixed commitments, and breaks. Two open hours are not the same as an empty day.
Reserve space for uncertainty
Do not allocate every remaining minute. Estimates are imperfect, messages arrive, and transitions take time. A plan with some unassigned capacity is more likely to survive contact with the day.
Select a short list
Choose the smallest group that addresses genuine deadlines and one or two meaningful outcomes. Treat priority as an input, not a command to schedule every important task immediately.
Keep the backlog intact
Not selecting a task for today should not erase it. Keep one main list and treat today as a temporary, editable selection from it.
Replan without judging the previous plan
At the end of the day, return unfinished work to the decision process. Adjust estimates or scope based on what happened instead of automatically carrying everything forward.