If you are working with fresh cherries, remove the pits by gently smashing them to expose the pit on the inside.
In a medium sauce pan add your cherries, sugar and water and bring to a boil
Once it has come to a boil, reduce the heat to medium and simmer for 5 minutes, stirring frequently.
After 5 minutes, place a fine mesh strainer over a large bowl and pour the cherry mixture over that.
Gently press the cherries in the strainer to release the remaining juices.
Discard the cherries and allow the cherry simple syrup to cool and come to room temperature.
Once the syrup has come to room temperature, cover with plastic wrap and place in the refrigerator for 4 hours to chill.
After it has chilled, you can transfer the simple syrup to a proper storage container or leave in the bowl until ready to sue in your favorite drink or cocktail.
Notes
Flavored simple syrup will last for a few weeks in your refrigerator.