I go through basically the same process each week to construct a 15-20 minute message.  Identify passage.  Research inductively and use commentaries.  Outline the basic message.  Manuscript.  Memorize.  All throughout prayer and listening is a vital part of the construction.  After these pieces are in place, there is nothing else to do but wait and see how God might use it.  Each person hears the message through their own personal lens.  God  uses all of this to speak into the hearts and minds of individuals.  The best sermons, in my opinion, are one-way dialogues whereby the hearer interacts with the speaker as if they are having a cup of coffee together.