Mottle the sugar and lime slices together in a pint glass until the juice from the limes and the sugar form a syrupy texture. If the solution looks watery, add more sugar, but don't overdo it. Leave the lime slices intact in the glass. Add the berries into the mixture and mottle again until the berries have be crushed into tiny pieces, but don't pulverize the mixture into a mash. Add the Cacha?a into the glass, and be generous in your application. Add ice until it fills nearly to the top of the glass. Cover the pint glass with a shaker and shake well. Enjoy the drink throughout the evening.