There are plenty of cheap and fancy bands you can buy for your Apple Watch. Care to 3D print one? Adafruit has shared a guide that shows you how to do just that. The goal of the project is get you familiar with 3D printing with flexible filaments. Ninjaflex, the filament used, is flexible and can be 3D printed with FDM style 3D printers.
You are going to need Apple Watch connectors to complete this project. More info is available here.