John everyone plays and navigates the keyboard differently...
there is no one way to do it.....I play off the cuff using a full repertoire song list and what ever sounds I need at the time
for the song I'm singing to, one Reg for One song. Pretty much I mix and match so every time I play the song it's a little different depending on my mood. I don't like to be regimented to the same arrangement each time that is too boring for me. I enjoy creating and arranging on the fly as i play and sing more fun for me that way. BUt it may not be the way others play and that is fine also. There is no right or wrong ..the only thing that matters is
"What it sounds like"