Before reading this post please note: it took three and a half years of full-time research to gather the data for my PhD thesis; the three months refers only to the writing, which I did quickly at the end. I do not claim that everybody can write that fast, and, certainly, if you have not done the research it will be impossible. You probably won't write as fast as I did, but you might gain some useful insights from the way I approached it.
After almost 3 years, I was on the verge of quitting my PhD in the summer of 2006.
I had nowhere near enough results, the equipment I was using didn't work most of the time, and I could barely summon the motivation to get up in the morning.
So how did I turn things around, get the results I needed and write my thesis in 3 months?
1. Dealing with stress
After a near-breakdown, I started taking walks around the campus when I faced a problem in my research or found myself getting stressed.
I took the time to think about what I needed to do and get myself in the right frame of mind to come back and deal with the problem.
Previously I would have found myself killing time on the internet just to get through to the end of the day. This one change in habit probably saved my PhD.
2. Limiting the time available
Though my productivity increased once I figured out how to deal with stress, I was still doing experiments well into my fourth year.
I had a final submission date (at the end of my 4th year), but my research was still a bit chaotic. It wasn't focused on finishing.
My supervisor (the brilliant Professor Moriarty) then told me that I would no longer be allowed into the lab after the end of March 2007, and that I would have to write whatever I had.
3. Adapting and acting decisively
Because of the limited time, I had to make some tough decisions. Anything I did, I would either have to finish or let go. There would be some loose ends, but that was OK as long as I tied up others.
I had to decide not to do certain things, and focus with energy and determination on others.
Still, though, the thesis would be a little thin. So I took on a side project based on another student's research, which could produce some results quickly.
This side project produced the most interesting result of my scientific career.
4. Finishing research before writing
By the time I stopped doing experiments, I knew I had enough for a PhD. Not the best PhD ever, and not world-changing, but with two publications and enough data for another, I felt it was good enough.
Because I wasn't allowed back in the lab, I just had to focus on writing. The hard part was behind me. The results weren't going to change, so it was just a matter of making sure I was productive when writing.
It is much, much easier to write when you know the raw material isn't going to change.
I decided to work at home, not at the office, because there would be fewer distractions.
I got rid of the TV, and had no internet connection on my computer. The lack of internet meant I had to gather all the papers I would need beforehand, forcing me to think about what I would need.
I also set up a dedicated space (2 large desks joined together and a very comfortable chair, next to a large window for plenty of natural light), just for thesis writing.
6. Targets and consistency
I set myself a target of 3 months, broken down into targets for each chapter. This would give me about 3 months in reserve before the final absolute deadline.
I had a daily minimum target of 500 words, which I knew I could meet even on the least productive days.
This meant that because I smashed the target most days, I finished every day feeling good about my progress, which in turn meant I started the next day feeling confident.
The two most important parts of the day are the beginning and end. It's important to build momentum early, and have a routine for ending the day too.
At the end of each day I always left myself something easy to do to get started with the next day, so I woke up knowing what I was going to do.
I also tidied the desk at the end of every day, which also helped close the day mentally and stopped my brain going over and over the thesis at night.
8. Applying ruthless standards to what I included
Whether it was the lit review, or my own work, I cut anything sub-standard.
I focused only on the very best literature, saving myself a huge amount of time. It also had the result of associating my work with the very best in the field.
I only wrote about what I knew about, which made the thesis shorter, faster and easier to write, and of higher quality than if I had included everything whether I understood it or not.
9. Taking time over details that matter
I took painstaking care over the clarity of the writing, the diagrams and the overall look of the thesis.
If a diagram took 2 hours, so be it. If I couldn't find a high-quality image in a paper to paste in, I would re-draw it myself. Why? Because it adds so much to the feel of quality running through the thesis.
By applying obsessive focus to one detail at a time, I could make sure that I wouldn't have to do it again. This brings me to the final point...
10. One draft
I always edit as I write, with one goal only: to make sure I've expressed the idea in my head clearly on the page. I don't move on until I feel the sentence makes sense, with no ambiguity of meaning.
Clarity of thought is always the number one aim. But it is very difficult to come back to a piece of writing days or weeks later and sort out a mess of thought if you don't clarify your writing while the thought is still fresh in your head.
This means I was constantly re-reading and revising what I've just written, but also means that when I submitted something to my supervisor it needed very few revisions and saved months, simply by getting as close to "right" as I could the first time round.
I've had some comments on this post reacting as if I completed my entire PhD in 3 months. No, I did three and a half years of research first, then wrote the thesis. I also do not claim that anyone can write that fast, as it depends on a lot of different factors. This is why the title is "How I wrote...", not "How to write..."