Defining what done means is one of the Meaning Factcheck Usage

Wise advice on clarity

Defining what done means is one of the most important things you can do - David Allen
At its core, this is about creating a clear, physical finish line for every single task you take on. It's the difference between "work on project" and "draft the first three slides."

Wise advice on clarity

You must clarify before you can prioritize - David Allen
At its heart, this means you can't effectively decide what's most important until you've first defined what "it" actually is. Clarity is the non-negotiable foundation for any real prioritization.
To learn faster focus on understanding first and Meaning Factcheck Usage

Wise advice on focus

To learn faster, focus on understanding first and memorizing second - Brian Tracy
The core message is simple: true speed in learning doesn't come from frantic memorization, but from building a solid foundation of comprehension first.