Making sand balls is simple but a whole lot of fun. Make them small, make them large, different beaches will give you different results, getting the right mixture of sand and water will make a stronger ball. To find the right mixture of sand and water, move closer or further away from the water.
Things you can do with them once made:
Shotput: Draw a few lines and see who can launch it the furthest.
Rings: Draw a ring to stand in, and as many rings as you like away from you, then see who can land them in the rings.
Darts: Make a small ring, and larger rings around it, like a dart board on the sand, then stand away as far as you desire, then try shoot the bullseye.
Tag: Chase each other around like ball tag, if your hit, your in.
Splash: Throw them as high as possible to make the bigest splash, the bigger the ball the bigger the splash.