One of the biggest productivity lessons I've learned is that focus beats time.
When it's time to work, the phone goes away. Emails get shut down. Notifications disappear. Headphones go on.
Then I work in short, focused sprints.
Usually 20 to 30 minutes.
What surprises most people is how much you can accomplish when distractions are removed and all of your attention is pointed at one thing.
The goal isn't working longer hours.
The goal is creating focused pockets of time where real work gets done and momentum starts building.