Line 2 cookie sheets with waxed paper. Place candy coating in medium microwave-safe bowl. Microwave on HIGH for 45 seconds; stir until melted and smooth. If necessary, microwave an additional 20 seconds.
To make each snowflake, place 6 pretzels, stems toward center and bottom points touching, in a circle on waxed paper-lined cookie sheet. One pretzel at a time, hold tip of tree and dip in melted candy coating; let excess drip back into bowl. Place pretzel back in circle. Continue with remaining pretzels in circle.
To form top layer of each snowflake, dip 3 additional trees, one at a time, in candy coating. Place on top of first layer of pretzels with tips of 3 pretzels touching in center between pretzels in first circle. Drizzle tops of trees with coating. (Reheat candy coating in microwave for a few seconds if it gets too cool to dip or drizzle.)
Before coating sets, sprinkle each snowflake with decorator sugar. Refrigerate 5 minutes or until coating is firm. Thread ribbon through 1 opening in tree; tie to form loop.