I don't know about you, but it's really hard for me to say "no" to people. That's a good quality for us to have in life, I think, to a degree, but there comes a time when it can be detrimental to our writing.
If your schedule is too full to write, it might be time to look at all the things you're saying "Yes" to and maybe saying "No" to a few of them in the future.
See, there are lots of great things we can do in life. Some of them even feel like writing (think going to the library, surfing the internet, or even reading a writing how-to book). But if we're not producing the pages we'd like in our respective projects, it's time we did something.
I once asked Sibella Giorello, a fantastic author and good writing friend, her advice for aspiring novelists. She said, "Ask yourself: 'What do I love to do, besides write?' Then kill it."
Each of us will have different things to um . . . kill. Maybe it's your time on Facebook, going to the movies, or even reading a novel. I'm not saying you have to completely give up everything in your life besides writing. Not at all. Having outside interests keeps our wells primed. And they help to keep us sane sometimes too! But there's always something we can cut.
For me it's definitely internet time. What is it for you?