Thanks, great ideas! I think extra recess sounds like a plan.
I worked at a school that allowed the students to collaborate and make little raps/songs about dominating the state test. A teacher and media specialist helped them do a rough edit and then the videos were played every morning on every tv in the school. The kids LOVED creating the videos and then watching their friends.
Some of my schools do the "MSA pep rally". It is a way for K-2 students to cheer on K-3 students and gets the school excited about the test. Anything that gives students a feeling of pride may help motivate them on the test.
My school has the K-2 classes decorate the doors of the 3-5 classrooms with motivating messages. Our mascot is a cougar, so one of the messages is "Stay Paws-itive for MSA". On the actual test days, the 3-5 teachers provide breakfast for their students to motivate them to be on time, and to give them energy.