Where should careful audio cleanup begin?

I am finishing a home-recorded vocal for a small community release, and a few pauses contain a faint metallic edge that becomes noticeable on headphones. The take still feels honest, so I do not want to flatten it with heavy processing. I am trying to build a careful review routine before the final mix. I first save an untouched copy, then mark only the moments that distract me during a normal listen. After reading this comparison page, I made several short exports instead of changing the entire vocal at once. That seems more useful than trusting a meter alone. My main goal is to keep the singer's phrasing and breath detail unforced. Each separate adjustment should be easy to undo. I compare individual passages at the same volume. The repair must remain restrained. I keep simple notes for every test. A second listening pass often catches changes that looked harmless on screen. The final vocal should remain present. Every planned edit stays possible to reverse. I make one decision reversible. I would rather retain a minor flaw than introduce a new one. Which steps have helped you decide when a small artifact really needs attention? I am grateful for useful process tips.