Construct physical barriers to temptation so the internet loses and your laziness wins. Then get properly bored. Then do the work.
Do the work.
That's all the productivity advice you need, and the only useful productivity advice you're ever going to get. You can direct your attention to a million optimizations— email, meetings, notes, calendar, time tracking, goals, todo lists, time estimates, prioritization frameworks, quantified self sensors, analytics, apps, documents, journaling. But don't. Ignore all this, and do the work. When you do the work, everything else optimizes itself.
If the only thing you must do is the work, why is there so much productivity advice? Blog posts, courses, seminars, software? Because when there is demand, there is supply. Work is hard. People will latch onto anything to avoid doing it. The market is happy to oblige.
Work means sitting down, getting through that calculus chapter, and doing the exercises. No amount of productivity hacking will make that easier. You don't need pomodoro alarms, bullet journals, time tracking apps, animated explainer videos, or different color highlighters. Everyone doesn't learn differently. Everyone learns calculus in the same way— by doing the work. You need Rudin's book, a pen, paper, and time. More tools give you negative utility. They won't make the work go faster. But they will consume as much time as you are willing to waste.
Building a new startup? Same thing. Talk to users all day. Then sit down and write the code. Get others to join you. Repeat. People do new founders a disservice by constantly proselytizing how complex startups are. In one sense they are. But in another sense they're surprisingly simple. For a long time you're doing the same three things over and over. Sell. Code. Recruit. Then do it all over again tomorrow. Startups don't get built by watching startup advice videos on YouTube. They get built by doing the work. All you need is a laptop and a metrocard.
I read a lot of biographies. People who have biographies written about them have two things in common. First, they are obsessed. Second, they never stray from doing the work. John Carmack was obsessed with game engines. Orville and Wilbur Wright were obsessed with manned flight. Leonardo da Vinci was obsessed with the structure of things. So they would code, construct, and paint. That's not to say they did no meta thinking. Carmack published plan files, the Wright brothers maintained extensive correspondence detailing their experiments, and Leonardo da Vinci is known for his magnificent notebooks. But you'd be hard pressed to find them writing letters about writing letters. They were busy doing the work.
An important ingredient for doing the work is boredom. That's how I got into programming. School was boring. We had three channels of television, and they were almost always boring. I had computer games, but I sucked at gaming and games quickly got frustrating. I read all the books that we had laying around. The only thing left was BASIC. So I started there and never stopped. The simple reason is that programming computers was the most interesting activity around.
If boredom is a necessary ingredient, then portable internet is a disaster for doing the work. How are you supposed to get excited about anything if you're never bored? I don't know if I ever would have learned to program if I had modern internet. Why would I, if something more interesting was always a click away? This is true to this day. I can't get anything done when I'm online. There is always something on the internet that's locally more interesting or more important than writing the next paragraph, or threading a flag through a series of function calls, or reading a book. The only way I can get anything done is to turn the internet off.
So I do. I have a work computer, and a router with parental controls that blocks every possible internet distraction on it. No Twitter, no Hacker News, no YouTube. Router administration is set up so I can't make changes over WiFi. If I want to unblock something, I have to physically get to the router and plug in a cable to change the settings. I power off every other device. No silent mode, no do not disturb, no hibernation. Power off. Recently a reader suggested putting my phone in a kSafe (thanks Robert!) It works great, and now I’m doing that too. All this constructs enough physical barriers between me and temptation that the internet loses and my laziness wins.
Then I get properly bored. And then I do the work.