A focus block is only as good as the interruptions it survives. Planning and prioritization decide what to work on; reducing distractions is what lets that work actually happen. Most of it is small, unglamorous adjustment rather than willpower.
The main reason distractions are expensive is not the seconds they take but the time needed to return to the task afterward. Each interruption forces the mind to reload context. A workspace that interrupts every few minutes never reaches the depth that complex work needs, regardless of how many total hours are logged.
Notifications are the most controllable source of interruption, because they are settings rather than habits. A practical baseline is to make the default state silent and let attention be pulled deliberately rather than pushed constantly.
A phone face-down on the desk is still a prompt to reach for it. Moving it out of arm's reach during a focus block removes the easiest interruption without requiring any ongoing decision. The aim is to make the distraction slightly inconvenient, not impossible.
Meetings are interruptions that have been agreed in advance. They are not inherently wasteful, but a calendar fragmented into thirty-minute gaps between them leaves no block long enough for demanding work. Two habits help: grouping meetings into a part of the day so the rest stays open, and keeping at least one meeting-free block that is treated as a real commitment.
The routine below is one way to start a focus block. It is deliberately short, because a routine that takes effort to begin will be skipped.
Sustained attention is not continuous; it works in stretches followed by recovery. Short, deliberate breaks between focus blocks tend to preserve more total output than working straight through to exhaustion. The specific ratio matters less than taking the break away from the same screen that holds the work.
Protecting attention is mostly about removing prompts, not resisting them.
For background, the public overview of the underlying concepts is available below.
External reference: Distraction (Wikipedia) and Attention (Wikipedia).