It usually works better when they don't know what's coming... but whatever.

Tonight as I was making dinner I told the kids that it was time to clean up the toy room. Jake and Evie both came running up the stairs to complain. Jake said, "Well, I'll clean the toy room... and Evie will probably help a little... but Lila won't."  Evie quickly followed up with, "Yeah! Lila just follows around and makes more mess by playing with everything we're trying to pick up!" I sighed, and said, "I know you guys. What you need to do is put on a movie that she likes so she'll be distracted and you can clean up."  They both ran back down the stairs and at about halfway down I hear Evie yell, "Hey Lila! We are going to distract you now!"