Keep in mind that the strawberry syrup will thicken as it cools. If you would like your strawberry syrup even thicker, you can add 1 to 2 teaspoons of cornstarch to 1 tablespoon of water. Stir until combined and pour into the cooled strawberry syrup.   If the strawberry syrup is hot, I would recommend adding a small amount of syrup to the cornstarch mixture and stirring first. This will help prevent any clumping when you pour the cornstarch into the saucepan of hot syrup.  Allow it to come up to a boil and boil until the cloudiness from the cornstarch is gone and the syrup has thickened.