A mnemonic to children (well, everyone, really) about flushing the toilet. Flush It Every Single Time, Amigo! (Feel free to substitute another word for "amigo," especially if you are getting sick and tired of reminding the non-flusher to make the effort).
When I entered the bathroom and discovered that my 5-year-old daughter had once again neglected to flush the toilet, I yelled, "Nicole . . . FIESTA!" and she apologetically returned to flush.