I've always liked to write in coffee shops. There's some background noise--sometimes enough to be mildly distracting. But ideally, the chatter and music and espresso-making sounds all blend together into a pleasing white noise. Also, I'm a captive audience. I can't wander off and do something else. I have my coffee and I'm set up at my table. I'm there to work, and so I do.
Libraries are my second choice. They're a little quieter, which is nice, and they have a similar "captive audience" effect because everyone there is working on something. There is an air of industry. The only drawbacks are that (a) there is no coffee, and (b) occasionally I find myself wandering through the stacks, looking for interesting books.
Now that I live out in the country, it's not practical for me to go anywhere else to work. I'm in my own home, with all its distractions. There's usually a dog asking to go out or to play. Sometimes the s.o. is watching a baseball game (or heaven forbid, something more compelling) on the TV just a few feet away from me. If I'm desperate enough to procrastinate, I'll start doing laundry, dishes, or even home improvement. There's probably no more background noise here than there is at a coffee shop, but what's happening here applies directly to me; it's stuff I can act on. And that scuttles my attempts to write.
So lately I've been working with really nice studio headphones on. I put on a CD of Handel's Water Music and Fireworks Music just loud enough to drown out a baseball announcer. Some people can work to music that has words, but I can't because I start paying attention to the singer's words instead of to my own. Handel is perfect because it's forward-moving and powerful without being bombastic or in any way startling. The CD is more than an hour long, so there's no excuse to get up and change it. And the headphones have a psychological effect of attaching me to my desk. I feel as though I'm writing really well to Handel.
I'd be interested to hear how other people concentrate when they work. Do I just have a butterfly mind? Or does everyone have to take heroic measures to concentrate?