Why this is worth doing

Getting Things Done is a way to get commitments out of your head and into a system you trust enough to stop rehearsing them. David Allen’s phrase for that trust is “mind like water”: the right reaction at the right moment, and a quiet head the rest of the time.

This guide is written for Reminders on iOS 27 and iPadOS 27. Reminders can be that system on an iPhone or iPad, because capture is already with you. Siri, the share sheet, widgets, and Control Centre can land a thought in Inbox before you have decided what it means. On iPhone, the Action button and Lock Screen widgets are extra capture paths. The rest of this guide is how to decide, and how to see the right handful of actions when you are at home, out, or about to phone someone.

What usually breaks

People abandon GTD for a boring reason. The weekly review gets skipped, Inbox fills up, and the lists stop being true. The fix is a smaller system you will still open on a tired Thursday, plus a review short enough to finish.

A second failure mode is taxonomy. A tag for every room, app, person, and energy level feels thorough on day one and becomes a filing job by day ten. This guide keeps the required tags to the constraints that change what you can do next.

Modern contexts

Classic context lists assumed a desktop you sometimes sat at. That split is gone. If an action needs a browser, a notes app, or a bit of typing, you can almost always do it wherever you are. Calling that @computer hides it in a list you never open, or dumps everything into one useless pile.

The contexts that still change your behaviour:

Anywhere. The default. Reading, writing, booking, paying, deciding, sending a message you can send alone.
Home. Your body has to be there: a leaking tap, a form on the printer, the loft.
Out. Your body has to be somewhere else: the post office, a shop, a specific building. A location alert can nudge you when you arrive. The tag is what puts it on the list you glance at before you leave.
Calls. Another person has to be live with you. Messages you can send alone stay in Anywhere. “Next time I am already chatting to them” is the When Messaging switch, described in projects.

Energy, time available, and deep-focus work are real, and they are optional. They live in advanced so the everyday system stays at one tag per action.

Starting again after a break

You do not need a new app, and you do not need to design the perfect areas before you begin.

Give yourself one sitting:

Follow setup if the lists are not there yet. If old reminders are scattered about, leave them alone until step 3.
For twenty to forty minutes, dump everything on your mind into Inbox. Speak it to Siri if typing feels heavy. Projects, worries, errands, “I should text them back”, all of it. Capture is allowed to be messy.
Clarify Inbox using the questions in capture and clarify until it is empty. Old lists can wait; drag anything still true into Inbox and run it through the same questions. Delete the rest. Deleting a stale reminder is a successful outcome.
Do the weekly review once, lightly.
Stop. Do one action from the context you are actually in.

Someday is allowed to be untidy. Inbox is not. The review is what makes the difference.

A system you will keep

Trust comes from two promises you can keep:

Every commitment has a home, and Inbox gets cleared.
When you open Home, Out, Calls, or Anywhere, you see actions you could do in that situation, sitting under the project they belong to.

The weekly review is the practice. The tags are just how the phone or tablet groups the work.