I guess I would keep my phone away from me until my 15 min break arrives, have some noice canceling headphones on to encourage not getting distracted because of my ADHD, have a great playlist on, and always be honest with your self.
The most important thing is to have the courage to eliminate distractions, no matter how tempting it is. Create a comfortable and tidy environment, and it makes a lot of difference.
The main step is to change your mindset into the state of full focus, and that will be the first and foremost basis for you to adjust. The rest are, personal preferences