Creating the products
The AbstractFactory class only declares the interface for creating the products. It is the task of the ConcreteProduct class to actually create the products. For each family the best idea is applying the Factory Method design pattern. A concrete factory will specify its products by overriding the factory method for each of them. Even if the implementation might seem simple, using this idea will mean defining a new concrete factory subclass for each product family, even if the classes are similar in most aspects.
For simplifying the code and increase the performance the Prototype design pattern can be used instead of Factory Method, especially when there are many product families. In this case the concrete factory is initiated with a prototypical instance of each product in the family and when a new one is needed instead of creating it, the existing prototype is cloned. This approach eliminates the need for a new concrete factory for each new family of products.