If you don't have a cocktail muddler, smack the mint a few times between your hands and then carry on with the recipe.
Add the mint leaves and lime juice to a glass. Muddle the leaves a few times.
Add ice, simple syrup, and rum. Give a little stir.
Fill with bubbly water. Garnish with lime wheels and mint leaves and serve.
Video
Notes
Using fresh mint leaves is the key to a good mojito! Fresh lime is always a little zippier than bottled lime and you can use the limes to garnish the drink. Use a flavored bubbly water for a simple twist. You can add fruit to customize - try blackberries or raspberries.