The 41-year-old actor has agonised about his fashion choices for years, but he's been happy to take "tips" from his girlfriend.
During an interview with Jonah Hill for VMAN magazine's spring/summer issue, Channing shared: "It has been a journey. I grew up in the South, and you don’t wear anything but like, white T-shirts and chains everywhere.
"I had a year I called, 'the year of the fresh white tee.' [Then] I started getting seen as a model, and I went so deep into the highest fashion world that you possibly can. I was living in New York and [there], you find your own style.
"When I moved to LA, dressing became a bit of a chore, it was just another suit for another talk show."
Channing subsequently took a break from acting and he tried to transform his style during his hiatus.
He recalled: "I stopped acting for a while, life changed, and I really wanted to pay attention and figure out who I was - that was like four years ago.
"Look, I went on a little bit of a journey trying to do Balenciaga and all this s***. And I was just like, 'This ain’t me either. I don’t know what the kids are doing these days.'"
Channing has also taken fashion advice from some of his showbiz friends and his girlfriend.
He told Jonah: "Then some friends of mine, like you and Zo, were like, 'Why don’t you just wear what you wear? Why don’t you just be you?' You gave me some very specific style tips.
"I’m really enjoying finding my own voice and my own way with some very beautiful guardrails. Jonah, you basically don’t let me look like a fool. So I appreciate you. I’m only mad that it’s taken you this long to give me these tips."