It is simple, but you need to make sure that the strawberries are dry before you dip them in the chocolate. If you want to make tuxedo strawberries, dip them in white chocolate first. Dip them straight down into the chocolate. Allow the excess chocolate to drip off before you lay them down. Put them in the refrigerator for a few minutes to set. Then, dip them in the milk chocolate by dipping each side at an angle. This allows you to see the little triangle of white at the top. Again, allow the excess to drip off each side as you dip them. Put them back in the fridge to set up. To make the dark chocolate tie an buttons, use a toothpick.
Good luck! It's actually a lot of fun!