But when it comes to my own projects, particularly my fiction ... it's a lot harder to stick to what I've planned. I might have "write 500 words of novel" in my planner, but sometimes, a lot of other tasks get in the way. (Plus there's new Doctor Who and new Dexter out on TV at the moment.)
One thing that really helps me is to be accountable to someone. That might be Facebook friends, the Aliventures audience, or even just my husband.
Could accountability help you, too? It might look like:
Setting up a shared Google sheet with coworkers where you can all track your wordcounts or time spent writing. (I did that last year when working full time for Awesome Motive and it definitely helped. Some people joined in with art projects as well as writing: you can use this format for all sorts of goals.)
Telling your Facebook friends what your writing plans are for the week ... and updating them at the end of the week about how you did.
Joining a writing group (locally or virtually) where you bring work to share each time. Having a deadline and an audience can be hugely motivating.
Committing to a regular publication schedule for sections of a major project. That might mean publishing a blog post twice a month (and letting your audience know to expect it) or publishing a chapter of your fanfiction-in-progress every week.
Sharing your goals and progress with a trusted friend, fellow writer, or family member. I think this works best when you can be "accountability buddies" for one another, so you're both setting and striving for specific goals. You don't neccessarily both have to be pursuing writing goals.
Accountability can make a massive difference to how much writing you get done. If it's not something you've considered leveraging before, give it a try this week.