Focus is one of the most important things if you want to drive meaningful change. It can be trained.
Sit down thirty minutes and do your work. No distractions, no breaks, no walks to the kitchen for a snack or a glass of water, no telephone in sight, no notifications on the computer. Just plain and simple work. Do that for one day.
Then do fourty-five minutes the next day, sixty minutes the following, and ninety minutes on the fourth day. Between sixty and ninety you will find your limit. Take note and commit to sitting down, every day, and doing your work for that amount of time with no interruption or distraction. When the time is over, go on a break for ten-fifteen minutes, then back to work for the same amount of time. You should be able to do that for four to six times each day.
That really is all you need.