Rinse strawberries, leaving stems attached. Pat completely dry with paper towels. Let dry on paper towels on a rack for 30 minutes. Line a tray with foil or waxed paper.
Melt white chocolate in a double boiler or small, deep heat-proof bowl over hot (not simmering) water over low heat, stirring often with a rubber spatula. Stir until smooth. Remove from pan of water. Cool, stirring often, until temperature of chocolate is 84 degree F.
Pat berries dry with paper towels, if necessary. Holding a strawberry by its stem end, dip 2/3 of the berry into the white chocolate. Gently shake berry; let excess chocolate drip back into bowl. Set berry on the prepared tray. Repeat with remaining berries. If chocolate thickens, set it briefly over hot water until it's soft enough for dipping.
Refrigerate berries for about 30 minutes or until chocolate sets. Carefully lift strawberries from foil to unstick; return to foil-lined tray.
Melt dark chocolate as above; cool until temperature of chocolate is 88 degree F. Dip bottom 1/3 of each berry into chocolate; set berries on tray.
Refrigerate for about 15 minutes to set chocolate. You can store dipped berries for up to 2 hours in the refrigerator. Remove from refrigerator about 10 minutes before serving. Makes 10.