The design of smart jewelry can be challenging as it requires technical knowledge and practice to explore form and function. Adressing this issue, we propose ProtoFlakes, a design speculation for a modular prototyping tool kit for smart jewelry design. ProtoFlakes builds upon the our prior work of Snowflakes, targeting designers with limited technical expertise with a tool kit to make creative explorations and develop prototypes closely resembling the final products they envision. The design requirements for ProtoFlakes were determined by conducting ideation workshops. From these workshops, we extracted four design parameters that informed the development of the tool kit. ProtoFlakes allows the exploration of form and function in a flexible and modular way and provides a fresh perspective on smart jewelry design. Exploring this emerging area with design speculations informed by ideation workshops has the potential to drive advancements towards more accessible and user-friendly tools for smart jewellery design.