Have a special day every week. Children (like adults) love to have something to look forward to doing.
The special days can be something as simple as Bubble Day .. Set up a bubble table and have the children see how many bubbles they can fill up the room with (while blowing several bubble sticks everyone at the same time).
Another would be ‘Plane’ Day Make paper airplanes and fly them around the room or outdoors. Have contests to see which will fly the farthest or the fastest.
Have a book party everyone bring their favorite short read provide a special snack and take turns reading. Another option would be to read a book that has a coordinating movie read the book first then watch the movie during rest time and discuss it afterwards.
Backwards Day is always popular wear your clothes backwards, come to school in pajamas, eat dessert first, have rest time before lunch anything that gets the kids giggling.
Favorite Toy Day Let everyone bring their favorite toy to play with during free time.
There are so many options you could have a different special day every week for the entire year without repeating the event.
Some additional suggestions:
Camping Day
Carnival
Beach Party
Art Fair
Grown-up Day
Do something Special Day
Song Day
Fashion Show
Hat Day
Favorite Cartoon Day
Circus Day
Luau Day
Pajama Party
Puppet Day
and so many more!