Freeze First: Freeze any mix-ins for 15 minutes before adding them to the ice-cream maker. This will keep from raising the ice-cream's temperature. Strain: Shake chopped ingredients like chocolate or nuts in a mesh strainer to remove small particles. This will help to keep the ice cream smooth's consistency. Don't Add Too Much: Add no more than 3/4 cup of coarsely chopped (1/4 to 1/2 inch) mix-ins per quart of ice cream to provide textural contrast without dominating the ice cream. If using a potent ingredient (think crystallized ginger or peppermint candies) use only a 1/2 cup. Wait Until The Last Minute: Add the mix-ins during the final minute of churning to ensure everything is evenly distribute without interrupting the freezing process.