With a paring knife. Put the cherry on a board covered with a tea towel – so the cherry can’t roll around. Stick the point of the knife into the cherry under the stone. Push the stone upwards and out.
With an orange stick – yes, the ones you would use for a manicure. Cherry on a tea towel again. Poke the pointy end of the stick into the cherry to the stone. Dig, twist and out it pops. It takes a few cherries to get the hang of it, but it works.
With a cherry pitter. Pop the cherry under the little hammer and squeeze. Perfect. As well it should be, since that’s its only function in life. If you’re serious about pitting cherries, you should get one and just accept that for the rest of the year it will be cluttering up the kitchen drawer.