How to upgrade a computer safely?

I am planning to upgrade my computer with new components, but I am unsure about the safest approach to avoid damaging hardware or losing data. Specifically, I would like advice on the proper order of operations, such as whether I should update drivers or the BIOS first, how to handle static electricity safely during installation, and what precautions to take with my existing files and operating system before making hardware changes. Additionally, I am concerned about power supply compatibility and whether I need to reinstall Windows after upgrading the motherboard or processor. Could experienced users share their step-by-step safety checklists, common mistakes to avoid, and any tools or software that can help verify system stability after the upgrade is complete?