Special equipment: paper snow cone cups, optional
In a medium saucepan, stir together the sugar and 1 cup water. Bring to a boil and cook, stirring, until the sugar is fully dissolved. Remove the pan from the heat and mix in the lemon juice. Allow the mixture to cool completely.
Prepare cones or bowls of shaved ice and pour about 1/4 cup of the syrup on top of each.