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.
“The remedy for speech that is false is speech that is true. This is the ordinary course in a free society. The response to the unreasoned is the rational; to the uninformed, the enlightened; to the straight-out lie, the simple truth.”