Dissolve: In a medium bowl, combine the warm water and sugar. Stir until the sugar is completely dissolved and the water is clear.
Season: Stir in the fish sauce and your choice of acid (vinegar or lime).
Taste Test: Dip a piece of lettuce or a noodle to check the balance; it should be a perfect harmony of sweet, salty, and sour.
The Float: Add the finely minced garlic and chilies last. Stir gently to see them float beautifully on the surface.