This post from Douglas Toft talks about how to decide what to write in a note:
“If you’re not sure what information to capture, then take a cue from Tiago Forte and his concept of resonance: Don’t make any explicit rules about what to save. Just capture whatever resonates with you in the moment, for any reason — even if you’re not sure that you’ll ever use it.”
It’s wise to trust your gut, write down what ever interests you in the moment, and allow those notes to pile up over time.