Dream journal - what to focus on?

My partner has practiced a lot of lucid dreaming. She is good at it, I'm not. All in all, I'm a conceptual, low level beginner not yet recovered from too many years of academics. I sleep 7 hours every night, and as I've gotten all the intoxicants out of my system (I'm referring to chemistry here, not Kant and Plato) I remember my dreams! I've read about lucid dreaming a bit, and understand it's vital to keep a dream journal. Does anyone have tips/own experience on what's best to focus on in such a journal? I've asked my partner, but she gets a bit impatient with me.