"Fun" is <embedded> in function. To get more stuff done, we need to find ways to make work more fun.
Typically I like to write in the morning. Between 9-11 am is when I am most productive. I make a point to block out this time in my calendar and to dedicate it entirely to writing or researching.
According to Parkinson's law "work expands so as to fill the time available for its completion". For example, we give ourselves three days to finish an essay when in reality, it only needs four hours of undistracted focus to finish. If we were to hit the deadline and only had four hours left, we would complete the task within that timeframe. The most mind-boggling thing is that both results would be similar in terms of quality.
More often than not, it does not matter if we feel a spurge of energy to do anything. What matters is just getting started. Activation energy outweighs the average energy to keep going. To put it simply, just get started whether you feel like it or not. The rest will take care of itself.
Seth Godin, who has been writing every day for decades, mentioned on the Tim Ferris Podcast that there is no such thing as writer's block, just insufficient research or the fear of failure (i.e. being afraid to write un-perfect sentences). You can find Seth's blog post here. I heard this and was blown away, thus, leading me to create a blog section on my website where I try to formulate one idea or one observation into a nice chunk of text every day.
I use this online Pomodoro Timer (25 minutes of writing followed by 5-minute rest).
As with everything in life, consistency is key. I experienced this first-hand last summer when I learned how to swim at the delicate age of 25. In the beginning, it was incredibly difficult, my body would drown as I let go of the edge of the pool. But I showed up every day over the summer, practised with the kind feedback of good swimmer friends, and eventually got better.