Work on tasks one at a time, in sequence, until complete

Start with task one and do not move to task two until task one is finished — even if task two feels more appealing in the moment.

Why it works

Sequential execution prevents the partial-progress problem: starting multiple tasks and finishing none. Incomplete tasks impose ongoing cognitive load (Zeigarnik effect) without producing outputs. Sequential completion maximizes the number of tasks that reach done — delivering both the psychological completion reward and the practical output. The list also functions as a commitment that makes skipping a task costly to self-image.

How to do it

1. Begin each day with task number one. Do not read email, check messages, or do preparatory tasks first.
2. If task one is blocked (waiting on information), move to task two — but return to one the moment the block clears.
3. When task one is complete, draw a line through it and move to task two without pausing to review the full list.

Evidence

The cognitive cost of incomplete tasks and the benefit of sequential completion align with the Zeigarnik effect and task-switching research. Single-task execution reduces switching overhead and increases throughput on the items that matter most. (mechanistic)

Task-switching research is mostly on simple tasks in lab settings; the extrapolation to complex knowledge work is principled but the exact magnitude of benefit is not established.

Sources

• Zeigarnik (1938), on finished and unfinished tasks
• Rubinstein, Meyer & Evans (2001), executive control of cognitive processes in task switching, Journal of Experimental Psychology

Common mistake

Treating the list as a menu and choosing tasks based on mood or energy, which defeats the prioritization step entirely — the sequence is the whole point.