TL;DR
Notes are just placeholders for more complex thoughts, and are only intrinsically useful when they are:
- organized;
- searchable;
- self-contained, self-explanatory, or transcribed; and
- readable at a later date.
What you need is a process for organizing short-term, project-related information into a long-term storage format that carries context and supports information retrieval. Your tool chain (whether it's paper-and-pencil or something more complex) must support your process.
Think Process, Not Tools
First of all, as you are already aware, part of your problem is not having a methodology or process rather than a lack of tools. There are many schools of thought on how to take notes, and an exhaustive list would be out of scope for a Q&A site.
Your choice of Cornell Notes seems more suitable for studying than for information tracking, but that doesn't mean it can't work for you. However, a few other options include:
- Minds maps.
- Free-form notes in a central location, e.g. a composition book, with meta-data like names or dates at the top. I often use this technique myself.
- Time-stamped entries in a log file. For example, you can use Windows Notepad to create time-stamped log entries.
- Notebook-style applications like Tomboy, the OS X built-in Notes app, EverNote, MS OneNote, Google Keep, and so on. The list is quite long; picking one is a matter of subjective preference, and software recommendations are out of scope for most of Stack Exchange except for Software Recommendations Stack Exchange.
Think Retrieval, Not Format
While it's nice to have a standardized format for your notes such as standardized headers, time-stamps, or categories, the real issue you're facing is that you don't have a sensible organizational system or a data retrieval system. Your information-tracking process needs both.
In general, I find that electronic notes that support free-form searches make information retrieval a snap. In addition, any system that supports free-form reorganization into categories or into some sort of prioritization order (i.e. index cards, Trello cards, Tomboy notes) is often very useful.
The ways you want organize and retrieve your notes should drive your choice of note-taking tools and methodologies. It should never be the other way around.
Transcribe Promptly
Notes are generally intended as short-lived shorthand. Whether you use real shorthand, software with with custom keyword expansions or autocomplete (e.g. vim abbreviations), computer-based shorthand systems like KeyScript, or any other kind of note, the secret to making the information useful later is to use your notes as a placeholder and transcribe the information into long form as soon as practical.
As one example, you might use Markdown and Pandoc as follows:
Jot some free-form notes into a Markdown document using a new header (e.g. #) for each note. For example:
Arch. Disc. w/Bill
Embiggen widget stamper: throughput.
At least daily, go back into your Markdown document and flesh out your placeholder notes into detailed, structured text so that it will make sense later on, especially if you forget the specific context.
Architecture Discussion with Bill Bailey (2015-10-01)
- The current stamper only produces 1.5 widgets per hour.
- Make the widget stamper big enough to product 15k widgets per second.
- Profit!
Use Pandoc (or other similar Markdown rendering tool) to convert the Markdown into an HTML/Word/PDF document, and send the long-form notes around for validation within the team or for storage as a project artifact.
The "magic" here isn't the use of a specific tool, it's in ensuring that your shorthand notes are converted to readable documents (including sufficient context so that they're understandable in the future!) while you still remember what you really meant when you jotted down:
@bill re: story #16
on the back of a napkin, sticky note, or index card.
