Distractions are everywhere, but a few simple steps will help you focus on your writing.
Turn your cell phone off. Smartphones are wonderful tools on the go and terrible distractions when you're trying to write. Decide on a reasonable interval to not be checking messages (or Facebook), turn off your phone, and don't turn it back on until you've written for that whole interval.
Clear your desk. Clutter is distracting – not the least when deciding to clean your desk, vacuum your house, or do your laundry sounds more appealing than writing. Find a place to work where you don't see any clutter (or clear the clutter out of sight). If you can see a TV that's on from where you work, either turn it off or move somewhere else.
Plan breaks. If you write in 15-minute increments, stand up and stretch for two minutes when you're done. If you write for an hour, take a 5-10-minute walk before starting a new segment. It does wonders for your focus and attention – including getting rid of that distracting "I feel restless" feeling.
Make the noise work for you. Some people work well with a little background noise or music; others do best with quiet. Find out what sort of noise environment works best for you and set it up for where you work.
Write first, revise later. If you get caught up on writing the perfect first sentence, you'll never get around to writing the rest of your paper until it's too late. Embrace the fact that you will be revising your work and just start writing! Even if you ultimately don't like what you've written, the exercise of writing will help you determine what you do and don't want to say, and how. It's always easier to revise than to write from scratch.
Read Your Writing Aloud
One of the most effective ways of proofreading is to read what you've written out loud – or, even better, have a friend read it for you while you keep a close eye on the text. Do they add little words that you left out? Stumble over a phrase? Run out of breath mid-sentence? These all provide you easy suggestions about what to tweak in your paper.
Take Notes on Your Process
Write Down What Works and What Doesn't. It's great to know what needs working on and what should be left alone, but don't assume that you'll remember all of these details. When reading and revising your draft, make notes to yourself (you can use Microsoft Word's Comments tool if you're working on your computer) about what works and what doesn't. If you do this, you have a clear and direct record of what you determined needs to be done.
Finish with a Note to Yourself. When you are done writing for the day, write a short note to yourself with instructions for exactly what you should do first during your next session. That way when you sit down to write you won't feel lost and you'll be able to get started quickly and efficiently.