I always start with characters rather than with a plot, which many critics would say is very obvious from the lack of plot in my films - although I think they do have plots - but the plot is not of primary importance to me, the characters are.
“I don't plot the books out ahead of time, I don't plan them. I don't begin at the beginning and end at the end. I don't work with an outline and I don't work in a straight line.”
“A theory has only the alternative of being right or wrong. A model has a third possibility: it may be right, but irrelevant.”