Visual aides for the students to see your daily schedule. (particularly helpful for ESL and students with special needs)
I have used these little cards on a velcroe board for a student with autism, and I have also used them in a pocket chart. Once each activity is completed, it can be placed in an envelope so that the students can see what is coming next.
You can also buy Pics for PECs, which has a lot more material and is also exorbitantly expensive (maybe ask your principal to spring for it!)