Motivate yourself to write

Everyone is different and every single writer will have their own way of encouraging themselves to put words on paper (or Word document). This is just a list of a few things that I do.

Use stimulus: Every time the cold days of April and May* creep up and I begin to use my small heater for my room, the smell of that heater sparks a deep desire to whip out Skyrim and start a new character. i won't have played Skyrim for months and months and then suddenly its as if I never stopped. Similarly, as soon as Christmas is over, my older brother starts a new save of Lord of the Rings: The Third Age, and has done so for years. My point is that we associate different things based on pleasant experiences. When it comes to writing, I often make myself an instant coffee and - considering I'm mainly a tea drinker - the smell of it and the act of making coffee sets my subconscious into writing mode. So when I decide I need to do some more writing, I just turn on the computer and put on the kettle and that helps get me going.
*I live in Australia, so those months are approaching winter.

Keep Writing: This sounds like a no-brainer, but the times where I have found it most difficult to motivate myself to write is after I've taken a long break on the project. Sometimes, obviously, it's unavoidable and you have no choice but to spend weeks away from your writing, but if you have the chance to continue your work, you should. I'm not entirely sure why this is, but it seems to be the case with my writing anyway, but I'll do a little postulation based on experience. I'm not motivated to write when I feel stuck in a spot, or when I feel that there is a whole mountain to go before I get to the parts I want to write. Even forcing yourself to work for half an hour and do 300-500 words a day, the numbers quickly tick over and, more importantly, so do the scenes. When I am progressing and constantly encountering new ideas and places and characters, I find it much easier to continue writing every day, and then it feeds on and suddenly your project is well underway. It's similar to when you sit at your desk, the hardest words to write are the first fifty. I've spent half an hour on 200 hundred words, feeling like I'm wading through mud, then suddenly after two hours I've written 2000. This is the same sort of thing expanded into weeks rather than hours.
Secondly, if you're anything like me, you suffer from crippling self-doubt. I've found that the longer I leave a project (irrespective of how long I've been working on it) the more I feel that it is awful. I finally finished a book because I actually powered through and finished before this doubt could kick in and I scrapped it like I have so many other stories.

Set goals, give yourself the freedom to fail and give yourself breaks. This may sound conflicting with the above point - and perhaps it is - but I have found it important to schedule time away from my project such that I don't hate it and feel like it is controlling my life. Alongside this, give yourself deadlines and goals and don't be afraid to make them extreme. When I say give yourself the freedom to fail, I don't meant 'don't worry to much about doing work,' I mean set difficult (but not impossible) goals. I did not officially take part in NaNoWriMo, but I did give myself the task to write 50,000 words last November. I finished my assessments on about November 5 and went on holiday about November 27 but I really gunned for that 50,000. I ended writing somewhere around 40,000 and while I didn't actually reach my goal, it was a whole lot more than I would have otherwise completed. I had a deadline and a target and it made me work.

So I hope if you have gone Google searching for some writing tips, this helps you a little. Good luck with your writing.