In a large plastic bag, put in the orange juice, lemon juice, hoisin sauce, sugar, oil, ginger and garlic. Seal and shake to mix. Add wings, seal and shake to coat evenly. Refrigerate overnight or up to 3 days. When going to bake wings, put extra sauce in a small saucepan. Heat to medium. Mix cornstarch and cold water in a small bowl. Slowly add cornstarch mix to sauce to thicken. Bring to a boil, whisking constantly, and then turn down to simmer.