Listen to a guided relaxation (lots of free podcasts are available)
Deep breathing exercises (google "deep breathing exercises for kids" for activity ideas)
Go for a slow, easy walk with a friend or family member
Paint nails (or have nails painted)
Listen to Nature Sounds - waves, rain falling, etc.
Play with Playdoh
Color
Finger paint
Take pictures with a digital camera (photo scavenger hunt?)
Make a gratitude scrapbook
Any easy, relaxing craft activity - there are lots of kits at Target, Walmart, JoAnns, Michaels, etc.
Take a Bubble Bath
Take a Nap
Snuggle with a family member or pet
Talk to a friend on the phone
Taste Exotic Fruits
Smell Herbs, Potpourri, Scented Candles, different kinds of perfume
Smell & Eat Oranges
Have Hair Petted, Combed, Brushed, or Braided
Have Back Scratched or rubbed
Play in a sandbox
Play in a water table
Color, cut out, and play with paper dolls
Lie in the grass and watch cloud shapes
Draw with sidewalk chalk