Start by rimming your glasses with sugar. Either dip the rim of your glass in simple syrup or run the cut side of a lemon along the rim of your glass, then press the rim onto a plate covered with sugar. Place glasses in the freezer to set.
Add vodka, lemon juice, cranberry juice and simple syrup to a pitcher or punch bowl. Give it a good stir!
If serving immediately, add ice.
If making ahead, cover it and place in the fridge. When you're ready to serve, add ice and stir again.
