In a small or medium saucepan, whisk together water and sugar over medium-high heat. Bring to a simmer, stirring occasionally until sugar is completely dissolved.
Remove from heat and allow to cool or use immediately. If using in a cold cocktail, I do recommend giving it some time to cool before using.
Store in an airtight container in the fridge for 3- 4 weeks and use in your favorite beverages or recipes as desired.