What to do:
This idea is from +Rachel Jones and I think I have seen it on Twitter! She has lots of ideas, worth a follow!!
Simply play music as students enter, they have to unpack, sit down, be ready to start their starter/bell work/DNA activity before it stops!
Students who are ready first can pick the song for the next entrance?
Play a song to pack up too?
For other simple ideas like this- check this Teachers Hack post!!