This book focuses on how to develop electronic circuits that live in the wearable context. Here are some materials and prototyping techniques that fall outside of the scope of this book that could be fantastic additions to your wearable electronics projects.
There is a wide range of interesting non-conductive materials that are smart, responsive, or just plain fun. Here are a few to consider.
Chapter 8 presented LEDs as a way to provide visibility. There are also passive materials that can provide visibility without electronics.