I just tried a make your own / MYO iced mocha coffee recipe from an old Watkins cookbook. It was okay. I would probably change a few things like add more sugar, 1 cup less milk and more chocolate. Since it was an old recipe, I wasn't sure if I was to use cocoa powder or chocolate syrup. I used cocoa powder, but would probably use chocolate syrup next time. With a few changes, I would definitely make and use this recipe again. So here's the recipe.
Iced Mocha Coffee
1 cup brewed double strength coffee (I used 4 heaping tablespoons coffee)
4 tbsps Watkins cocoa
1/4 cup sugar
pinch of salt
3 cups top milk (I used 2% lowfat milk)
Brew coffee in coffee maker. Combine the coffee and cocoa in a pan on the stove and stir until thoroughly mixed. Bring to a boil and then add the sugar and salt. Boil for 3 minutes and stir constantly. Add milk. Chill and serve over ice.