If you feel you have the right key, you try to make some phrase or sound that will fit.
“I remember when I was coming up, the music stores where you could get guitar strings was where I got my records from. Now the place where you get your records from is where you can get your DJ mats and your mixers.”
“Now, on the St. Louis team we have Who's on first, What's on second, I Don't Know is on third.”