The world has seen an influx of connected devices through both smart devices and smart cities, paving the path forward for the Internet of Things (IoT). These emerging intelligent infrastructures and applications based on IoT can be beneficial to users only if essential private and secure features are assured. However, with constrained devices being the norm in IoT, security and privacy are often minimized. In this paper, we first categorize various existing privacy-enhancing technologies (PETs) and assessment of their suitability for privacy-requiring services within IoT. We also categorize potential privacy risks, threats, and leakages related to various IoT use cases. Furthermore, we propose a simple novel privacy-preserving framework based on a set of suitable privacy-enhancing technologies in order to maintain security and privacy within IoT services. Our study can serve as a baseline of privacy-by-design strategies applicable to IoT based services, with a particular focus on smart things, such as safety equipment.