Use an outliner without turning it into a system.
An outline can be useful before it is complete. Start with the note in front of you and add only the structure that makes the next step easier.
Write the note before naming the structure
Begin with one line and keep using Enter while thoughts arrive. Headings and groups can come later.
Use indentation as a relationship
Indent a line when it explains, supports, or belongs to the line above it. Move it back out when that relationship changes.
Keep the current view small
Collapse details you do not need, or focus on one branch as the current view. Search across pages when you need to recover an older line.
Start a simple outline
Open Jotfold and write the first line before deciding what the page should become.