Wearable skin-contacting devices are extensively studied for their ability to provide convenient and safe health monitoring. A key aspect that controls their performance are the properties of the device electrodes. Optimizing electrode structure, and the materials they are made from, can improve device functionality. Here, we discuss the various properties required for optimal electrode performance, including mechanical, electrical, and biocompatible factors. To address these challenges, we consider alteration of electrode structure, the development of flexible or soft conductive materials, and the creation of hybrid structures. Additionally, the integration of artificial intelligence is proposed as a promising direction to achieve smart devices. As well as outlining essential characteristics for high-performance wearable skin devices we also offer insight into possible future applications.