Some things you have to decide.
The rest you deliberately don't.

What is pulling me

Say what happened first, including that it hurt. Then decide what this time is for.

Leave arrangements vary. Some employers set the terms, some need you to ask first, and some leave room to negotiate. Say which applies to you, because each one leads to a different next step.

A start date gives the gap an edge. The next section is about keeping that gap from filling up with work you are not being paid for.

The usual way a gap goes wrong is that people start the job early and call it preparation, or being ready for day one. You are not being paid yet, and the work will still be there. Decide now what counts as the job and what you will not touch.

What I will not do before the first day

It is still you who goes, so this time is a chance to learn from the work you did. Looking back from the outside, what did you see that you do not want to experience or act out again, and what did you learn that you want to carry forward?

What I do not want to experience or repeat

What I learned and want to take forward

Answer this before anything about ambition. How much of a break you can take depends on how much room you have, and there is no right answer.

Ambition is the most common way to ruin a sabbatical. Choose your level on purpose.

A schedule makes a sabbatical worse. A place, a time of day and a few open questions do not. Pick where you will think, when, and about what.

You have a start date, so the gap has a length already, and you are not here to work out whether you can pay the bills. This is about the extras: the things you would not normally spend on, and want to.