Good modeling practice is based on robust design intent. This just means that you should try to build parts that can adapt easily to changes. This section of the book begins with things you need to know in order to make good models—models that react predictably in drawings and that update properly with changes. A robust design intent will make downstream operations easier.
Creating simple parts will help you understand the techniques used in more complex modeling projects. Learning on simple tools and then expanding your skills will help you understand best-practice issues, which will make you a better contributor to a team environment.