I have never had a class of students who all complete their work at the same time. I always need to have something for the students who finish early to work on. Instead of always copying worksheets, I like to have a list of activities for the students to choose from.
Having a posted list of items for students to work on helps to build the routine in the classroom. It cuts down on students wandering around the room and engaging other students who are trying to complete their work. Having these fun activities posted also works as incentive to some of the students who might work at a slower pace.
This is a set of cards that go in a regular pocket chart. It contains activities for early finishers to keep them engaged and active while the rest of the class finishes their work. Cards include: Read Your AR Book, Practice Math Flash Cards, Clean Your Desk, Make a List, How Many Words Can You Make With the Letters In: (various holiday and seasonal words) and many more.
In my class I change out the cards often, depending on the interest of the students. They love coming into the room in the morning and checking out what's on the I'm Through board!
Note: For teachers in Catholic schools there is a Catholic school version with religious activities included.