How do I keep my C drive empty?

I'm curious, how does one effectively maintain an empty C drive? Is there a specific strategy or set of practices that you recommend to ensure that the C drive remains free of unnecessary files and programs? Are there any tools or software that can automate this process, or does it require manual intervention on a regular basis? Additionally, what are the potential consequences of neglecting to manage the C drive's storage capacity, and how can one avoid these issues?