Wash the strawberries thoroughly and set them aside to dry on paper towels.It's very important that the strawberries are clean and very dry. Excess moisture will prevent the chocolate from sticking to the strawberries properly or even make it seize. Prepare your sheet pans or trays by lining them with with parchment paper.
Chop the dark chocolate and the white chocolate and place it in separate glass bowls.
Melt the chocolate in the microwave, in 30 seconds intervals, mixing with a small silicone spatula between the intervals.
If your bowls are too wide and the chocolate isn't deep enough for you to comfortably dip the strawberries in it, transfer the chocolate into liquid measuring cups.
Holding your dry and room temperature strawberries by the stem, dip them in chocolate in one smooth motion, leaving just a little bit of strawberry uncovered. Shake or spin the strawberry so that excess chocolate can fall back into the bowl or cup and place it on the parchment paper.
If you want to add any toppings, now is the moment to do it. For the white lines on dark chocolate or dark lines on white chocolate, you don't have to worry -we'll do them at the end.
If you're not sure you can work fast enough and are worried about the chocolate hardening, simply place the chocolate bowls in a baking tray with hot water and mix the chocolate every now and then.
When you've finished dipping all your strawberries, pour the leftover chocolate into small piping bags.
Snip a small tip off with a pair of scissors and slightly squeeze the piping bag over the chocolate dipped strawberries to create contrasting lines.
Make white lines on the dark chocolate covered strawberries and dark lines on the white chocolate covered strawberries.
To get very straight lines, go back and forth on a wider area than your strawberries, keeping the strawberry in the middle.For a more rustic look, simply create lines on your strawberries including the curves on the sides. If you'd like sprinkles only on the thin lines, put them on right after piping the lines.
Place your strawberries on a platter, let them set for about 20-30 minutes, and then serve!