I have a theory that different things work for different people and not all things work for all people. Any particular book or blog post should not be taken as a gospel but rather a set of tools from which you can try and pick up what works for you.
What worked for me: (1) getting more sleep - counterintuitive, as one gets less time to be productive, but I find that sleep deprivation affects my mood, attention, and executive function big time (2) writing it down and drawing up my day hour by hour. Even if I do not follow the plan to the tee - it helps me visualize the day and find large chunk of times that are best for getting into the zone (3) batching up small but mundane tasks and sticking them into the short available chunks of time that would not be good for deep work, then focus on this list of tasks and racing to compete as many of them as possible, using the short rush of pleasure of completing one task as a burst of energy for the next one and create momentum.
What worked for me: (1) getting more sleep - counterintuitive, as one gets less time to be productive, but I find that sleep deprivation affects my mood, attention, and executive function big time (2) writing it down and drawing up my day hour by hour. Even if I do not follow the plan to the tee - it helps me visualize the day and find large chunk of times that are best for getting into the zone (3) batching up small but mundane tasks and sticking them into the short available chunks of time that would not be good for deep work, then focus on this list of tasks and racing to compete as many of them as possible, using the short rush of pleasure of completing one task as a burst of energy for the next one and create momentum.