I finished the book Deep Work last month while, appropriately, working long hours from an extension ladder on my house.
This article sums up the 4 major rules of entering into deep (focused) work. Should take you less than 10 minutes to read, and if the topic is interesting to you, check the book out also. This theme of our diminishing attention is growing as our world grows more noisy and distracted by the day.
Get at me anytime on this topic, it's something I read and work on daily.