The pop superstar penned the lyrics to 'ME!' - which features Panic! At The Disco's Brendon Urie - and 'The Man' from her album 'Lover' whilst shooting the Netflix documentary and didn't find having cameras in her face "intrusive" because she was so in the zone whilst songwriting.
In a sit down chat with director Lana Wilson shared on the streaming service's YouTube channel, Taylor said: "That was the first time I've ever had a camera crew in the studio, it's always been really off-limits."
The 'You Need To Calm Down' hitmaker also shared that her phone is where she stores all of her ideas and edits for songs.
She added: "You weren't invasive at all. I just think I was really in my feelings, I just get really in it when I am writing a song.
"I disappear into my phone because my phone is where I keep my notes and where I keep my editing.
"Every time I wake up in the middle of the night, or every time I think of a title, or every time I think of a common phrase and flip, I love doing that, I will put it in my notes.
"There is real speed to it, too."
The 30-year-old singer added that her "favourite" aspect of the creative process is when she realises she is onto a great idea.
She said: "The ideas are my favourite part of everything I do.
"That moment where you're like, 'Oh I know what it's called,' or 'I know what the hook is now.'
"I have to capitalise on the excitement of me getting that idea and see it all the way through otherwise I'll leave it behind and I'll assume it wasn't good enough."