2/3-1 cup sugar
In a small saucepan, bring 2 cups water to a boil. Add 2/3 cup to 1 cup sugar, stirring to dissolve. Remove from heat.
Roll lemons on counter top to loosen juices. Cut in half, and squeeze juice into a 2 quart pitcher. Add simple syrup (sugar/water), and dilute with cold water to fill pitcher. Chill well before serving.
You could easily substitute limes for the lemons. You can also add strawberries, lavender, or mint!