What's your go-to concentration technique that actually works? Not the obvious stuff like 'turn off notifications' - I mean techniques you use daily.

I've been struggling with focus lately and I'm curious about what actually works for people who manage to stay productive. I've tried the usual advice - Pomodoro technique, turning off notifications, working in quiet spaces. Some of it helps a bit, but nothing really stuck as a game changer.
So when you're really productive and concentrating well at work, how do you reach that state?
I'm especially interested in:

- Do you have a specific routine or ritual before starting work?

- Is it about the environment, mental tricks, or something else?

- What's the one thing you'd be completely lost without?