Measure 1 to 2 cups of water and place it in a saucepan on the stovetop. Bring the water to a boil over medium heat. The sugar solution is easier to make if the water is boiling.
Pour the sugar into the water 1/4 cup at a time. Stir the water and sugar constantly. Keep adding sugar until you saturate the water and no more sugar will dissolve into the boiling water. When you see sugar granules begin to settle onto the bottom of the pan, you have properly saturated the solution. You will need approximately twice as much sugar as water. For example, if you boiled 2 cups of water, you will add approximately 4 cups of sugar. Remove the saucepan from the burner when you finish saturating the solution.
Tie a piece of string to a pencil and fray the loose end with the blade of the scissors. The sugar crystals prefer to grow on frayed string rather than a smooth string.
Hang the string into the glass jar so that it does not touch the sides of the glass. Extend the string almost to the bottom of the jar so that you have sufficient area to grow the sugar crystals. The pencil should rest across the top of the jar.
Pour the sugar solution into the jar and check the string to make sure that it hangs properly into the sugar water. Adjust the string if necessary by moving the pencil or by winding the pencil to shorten the string. Tape the string and pencil in place on the jar.
Cover the jar with a tissue to keep dust out of the sugar water. Leave the jar on your counter for several days to a week. Sugar crystals grow slowly but over time will become very large.