One idea for a YouTube channel without showing faces could be a cooking or baking channel. The focus could be on showcasing delicious recipes and providing step-by-step instructions for viewers to follow along with. You could film the hands of the chef as they prepare each dish and use voiceover narration to guide viewers through the process.
Another idea could be a DIY crafts channel, where you showcase different projects and provide tutorials on how to make them. You could film your hands as you work on each project and use voiceover to explain the steps involved.
Alternatively, you could create a music channel where you showcase your musical talent, either by playing an instrument or singing. You could film your hands as you play or record audio separately and overlay it onto footage of scenery or abstract visuals.
Finally, you could create an educational channel, where you teach viewers about various topics. You could use animations and graphics to illustrate your points, and use voiceover to convey information.