For lists of ideas for attention grabbers to try out in class, click here : GRABBERS
To be most effective, you need to accustom your students to one before moving on to another. Once you have built up your repertoire, they will be happy to go along with whichever grabber you choose to use for the lesson on that particular day.
Great classroom management technique, injecting language and having a bit of fun in the classroom, all allowing you to save your voice and avoid the “Now listen to me everybody” approach.