Dry the strawberries: Wash the strawberries and pat them completely dry with paper towels. Any moisture left on the surface will cause the melted chocolate to seize or slide off.

Prepare the tray: Line a baking sheet with parchment paper and set it near your workspace. This keeps the dipped berries from sticking once they're coated.

Melt the dark chocolate: Combine the semisweet chocolate chips and 1 teaspoon coconut oil in a microwave-safe bowl. Heat in 20-second bursts, stirring between each, until smooth and glossy, about 1 to 2 minutes total.

Dip the berries: Hold each strawberry by the green cap and dip it into the melted chocolate, tilting the bowl so the chocolate covers about three-quarters of the berry. Let the excess chocolate drip off for a few seconds.

Add toppings immediately: Sprinkle chopped nuts or sprinkles onto the wet chocolate right away, before it starts to set on the surface. Place the dipped berries onto the parchment-lined tray.

Melt the white chocolate: In a separate bowl, melt the white chocolate chips with 1/2 teaspoon coconut oil the same way, in 20-second microwave bursts, stirring until smooth.

Drizzle the berries: Dip a fork into the melted white chocolate and wave it back and forth over the dark chocolate shell to create thin drizzle lines. Repeat over all the berries.

Chill to set: Refrigerate the tray for about 15 minutes, until the chocolate turns matte and firm to the touch. This keeps the shell from smudging when you handle the berries.

Serve: Arrange the finished strawberries on a plate or in a small box. They taste best within a few hours of dipping, while the berries stay crisp under the shell.