How to test if wire is live?

Hello there, I'm curious about how one can safely and effectively test if a wire is live. I understand that this can be a dangerous task if not done properly, so I'm seeking guidance from experts. What are the recommended tools and steps to follow when testing for live wires? Is there a specific voltage tester that works best for this purpose? Additionally, are there any safety precautions that I should keep in mind to ensure my own well-being while performing this test? I'd appreciate any insights you can provide on this matter.