1. Rim glasses with sugar. 2. Do this by slicing a lime in half and then almost in half again. Slide the rim of glass between two sides of the lime half and squeeze the lime together. Run the lime around the rim of the glass.3. Place sugar in a small bowl and slowly twirl the glass as you press it into the sugar. You can also dip the glass into the sugar if preferred.4. Next mix drink.5. Mix watermelon juice, lime juice and vodka in a shaker.6. Serve with a lime slice on side of the glass. Enjoy!