Pen + paper, and sometimes Omni Outliner. I'm a fan of Omni over plain text tools like Obsidian because it makes the sub-nesting and drag and drop hierarchy ve

Pen + paper, and sometimes Omni Outliner. I'm a fan of Omni over plain text tools like Obsidian because it makes the sub-nesting and drag and drop hierarchy very pleasant (almost Roam-like) but is also a fast native Mac app.