In a cocktail shaker, muddle together vodka, strawberries and lime juice.
Strain into a mule mug filled with ice.
Top with ginger beer. Garnish with fresh lime or fresh berries.
Notes
Don't have fresh strawberries? You can substitute strawberry vodka instead of muddling fresh ones. You could also use a splash of strawberry syrup. Don't have or want to use vodka? Use your favorite spirit. Gin especially would be so good in this drink! Bourbon, rum, tequila and brandy would all work well too.