The 36-year-old was asked to compile tracks for Lioness: Hidden Treasures with Salaam Remi, but at first he turned down the offer.
He told British newspaper The Sun: 'I said no at first because it felt a little strange and I was still not really coming to terms with losing someone that close to you.
'Then I heard the vocal (of Will You Still Love Me Tomorrow) and thought it was amazing and that I could do something special with this, which Amy would love. That was when I decided to do it. She sounds incredible.'
The posthumous album is a 12-song collection of unheard and unreleased alternative versions and new songs.
Ronson added that making the record was sometimes difficult: 'It was hard making this album. Listening to her voice, you forget what happened. You work on it as if she's still alive.'
He added: 'She was just an incredible singer. She had so much power in that tiny frame. Lioness is an appropriate name for this album because she could just roar at any moment and you would wonder where that force came from.'
Winehouse was found dead in her flat in Camden, London on July 23 this year.