Go outside!  Enjoy some of that summer sunshine.

Run through a sprinkler!

Dip your toes in  the river/ocean/lake that you are closest to.  Then take a running start and do a cannonball into the water.

Buy two popsicles, and share one with someone you love. 

Don't let another day slip by without smiling into the sunlight.

Then, sit outside at night, and stare at the stars awhile.  Find the star you used to wish upon as a child... and dust it off.