Outliners are fun toys and amazingly useful tools, but not everyone uses them, or has one handy at all times. Here's one trick you can use when dedicated apps aren't an option for some reason. Simply use any old text editor to write a file where each line is indented (with tab characters) according to its position in the tree. Something like this:
Outliners Work with text arranged in trees, like the sections in a book. Can handle high volumes of text. Mind mappers Make pretty 2D diagrams. Often use icons and colors to good effect. Examples of both TreeLine Can work with highly structured data. My Mind Runs in the browser!
Sure, you don't get folding or structure editing, but it's as low-tech as it gets. As a bonus, this format can be imported or exported by a whole bunch of tools, such as the aforementioned TreeLine and My Mind.
(Note that the former is okay with an outline having multiple top-level entries like that, while the latter expects a single root node and will create an empty one for you. Other mind mapping apps are smarter.)
That's really it! A simple trick that can go a long way, and can let you do more later. And remember:
- A good outline balances breadth and depth; watch out for subtrees that want to be their own document.
- In the end, every outline is linear. It may have links between nodes, and a two-dimensional component, but no matter how you slice and dice it, you have to consider how it reads in order from top to bottom.
Hope this helps!