A mechanical stoner makes pitting cherries easy. The blunt spike pushes the stone through the flesh, ensuring the fruit retains its shape and precious juices are retained. Alternatively, you can use the point of a vegetable peeler - insert it in the stalk end, rotate it around the stone, then scoop it out.
Pull out the stalk and discard. Place the cherry, stalk-end up, in the cupped side of the stoner. Hold the fruit firmly and squeeze both handles of the stoner tightly together until the stone is pushed out.