Good on you AvgasDino.
I have been helping a family friend compile some of his memories and stories during the war as a B-24 bomber captain and afterwards. My uncle, and inspiration for my career, flew for Eastern then American, spanning the days of hulking radials to jets, has also been coerced into putting down his experiences for posterity.
Our B-24 man has been using a handheld recorder, after having tried typing it all out on an ancient manual typewriter, whilst my uncle is using a combination of hand written notes, his journals, and a cell phone voice recorder app.
For anyone struggling with memory and structure, we have found a couple of tricks using categorization such as aircraft type, girlfriend, domicile, model of automobile owned, and night stops, all of which have provided fertile starting points to jump off from.
One of the greatest 'methods' we've discovered, although not always possible, is to organize a meeting of old friends and quietly record the interactions, such as, "remember old so and so" or "what about that time you saved the day..." or "whatever happened to..." with each friend in turn providing details or corrections that had been since forgotten.