I'm Tony, a certified Pro Tools user with Avid. I've been audio engineering for 10+ years and my editing suite is acoustically treated and my product transfers well to various listening environments.
I start with the most obvious sound issues and work my way out until I hear clean clear pristine audio. Artifacts like hisses, pops, clicks and hums are all removed with various sound editing and sculpting tools via software like iZotope, Waves and other plugins.
I can also use time stretching/compression capabilities to match different takes of vocal performances from track to track. I can also control D-essing and plosives.