From Joel Chan, this process for synthesizing notes is the best I've seen. It's a bit academic in nature, but with a careful read can be easily understood and you could have a new process for note-taking. I know I do.

The process goes like this

1. Begin with a set of question notes and papers
   • Every paper or source is read with these questions in mind.
2. Create observation notes
   • Observation notes have the potential to inform one or more questions that you started with.
   • Each observation note is grounded in at least one quote or context from a source and then directly linked to a question note.
3. Develop synthesis
   • What does the literature have to say about the questions of interest?
   • Synthesis notes also get explicitly linked to relevant question note.
4. Compose and combine synthesis notes and questions of interest into arguments and theories.
   • If done well, this process will reveal even more questions. That's okay. Go back to the question phase.

Example images

I reccomend you read the entire article. Do so here.