My work process has not varied much over the years. Every job starts with pencil to paper, working up various sketches and ideas to present to the client. Sometimes I will add washes or play with various color screens in photoshop to see where that may take me.
One thing that has changed over the years is that I find myself working larger for some projects. This has helped me to work looser and achieve various textures which can be a bit tougher when working small.