For me the single best thing has been to schedule "deep work" first thing in the morning. blocking out 1-4 hours to work with no music, no access to my phone an

For me the single best thing has been to schedule "deep work" first thing in the morning. blocking out 1-4 hours to work with no music, no access to my phone and if it makes sense (it rarely does) no internet connection. I find that if I start my day like this I'm more easily able to focus for the rest of the day even if I return to a more normal working environment. I don't have to be at an office at 9am though so it might be less achievable for you. While on the internet I use a pomodoro timer and website blockers to try and keep me focused on the task at hand, both of these are pretty crude solutions that can sometimes even be counterproductive though. (shameless plug: I'm working on an "intelligent" website blocker in my spare time - https://awakely.herokuapp.com https://awakely.herokuapp.com) Modafinil/provigil can be helpful if you have a clear and inflexible plan for what you need to do during the day. I find that they often make things even worse once I do get distracted though. And they are more conducive to productivity on simple repeatable tasks than complex, difficult tasks that require context switching to learn new things. I take 100mg first thing in the morning and drink extra water to prevent headaches. Making lists of what you want/need to accomplish that day can be useful for keeping you accountable to yourself, but again they often work better with well-defined tasks, otherwise you end up with your original list half-complete because you had to do other things that you couldn't anticipate and the day ends up feeling like a failure. A low-carb/slow-carb diet has been helpful for keeping my focus more constant throughout the day, especially a fat/protein based breakfast. Some advocate a ketogenic diet for this too, although I haven't gone that far myself. Getting 8 hours of sleep each night makes a huge difference. Strangely, I actually find ~4 hours sleep makes me more productive than 6, this certainly isn't good long term though. As others have said, your biggest issues is probably just attempting to work 12 hours a day in the first place - most people just can't pull this off on a regular schedule.