To make lemonade syrup:
Combine sugar, water, and salt in small saucepan. Bring to boil, reduce heat and simmer 5 minutes. Remove from heat and cool slightly. Combine with lemon juice and mix thoroughly. Keep in covered container in the refrigerator.
To make lemonade:
Combine 1 part lemonade syrup to 3 parts water or soda water. Serve over ice or frozen fruit pieces such as raspberry or pineapple. Garnish with mint.