It wasn't so much a New Year's resolution (because I started before the new year), but around Christmas time last year, I decided that I wasn't just going to think about writing every day, I WAS going to write every day.
Part of that was a desire to get the first draft of Intertwined done (which I did, yay me), but also to build a habit, to make it the normal, everyday occurrence, rather than "oh I'll do some writing today". And now, looking back, I'm still doing it.
I finished the first draft of Intertwined at the start of March, and I'm currently reading through the draft, making notes for changes and tweaks, as well as things to add or remove. That's in addition to the daily writing that I'm doing. I've been working on a rewrite of a manuscript I wrote a long time ago, so it's been interesting to apply what I've learned over the years, and what's really surprised me, is how different the scenes are while also leading the story in the same direction.
Anyway, now that I've been writing every day for just over 3 months, it really has become a habit now. I need to do it. I can't go to bed knowing I haven't sat down and gotten my quota out for the day. That novel I'm rewriting? I'm at 25000 words already, and I'm not even sure what I'll do with it - but as an exercise that keeps me writing, keeps me thinking in terms of character, story, plots, and themes, it's invaluable.
So yes, I'm writing every day, and if I can do it, anyone can. So if you are writing every day, that's brilliant. If you're not, try and do it for just a week. Then try and keep it going for another week. And a week after that. Pretty soon, you won't want to break the streak.