I've got a lot of particulars when it comes to writing. I find that what keeps me working can vary immensely depending on the language I'm writing in, the genre, being on holiday or having to manage a few minutes out of a heavy work schedule, ... a ton of factors.
I believe the best advice one can give a writer who has trouble avoiding distractions is to 'know thyself'. What triggers the distraction? Perhaps you can't stand the idea of dirty dishes in the sink. Or maybe your mind starts wandering after x minutes. Perhaps seeing other people working eagerly motivates you to follow their example... or maybe it makes you feel frustrated and kills whatever creativity you had at the moment.
Once a writer understands what kills the mood and what strengthens their willpower, then they can establish a sound routine.
However, it is easy to run out of ideas and strategies, especially with a fickle muse. Reading about other writers' strategies can spark new ideas and help to mature one's own routine. The OPs suggestion of having a 'writing mate', for example, was new for me and I find it quite interesting, even if I can't really focus on writing when I'm sharing the room with someone else (but knowing someone else is working hard in the next room, on the other hand, might still work as motivation).
But let's talk about easily distracted minds. I'm one, and I'm not. If I have a scene burning inside me, I am capable of sitting at the computer and working for over eight hours without a stop. I won't notice hunger, thirst, not even a full bladder. Nothing will distract me. It's obsessive and, let's face it, unhealthy. But if I'm not sure how the scene will play out, then breathing itself becomes a distraction. I sometimes find that lying down in a dark room as if I were about to take a nap can get my mind a bit more focused. Either that, or I really end up napping and then wake up with a fresh mind. It's a win-win situation in any case.
In my particular case, I do not have one routine but a variety of them. The strategy that works best one month may be the worst option the following month. I'm erratic, you see. It means my routines are constantly changing and it's very often a matter of playing it by ear. More often than not, I simply change tasks. If I can't edit right now, I'll do some tidying and will go back only when my head feels alert.
One thing, though, I advise to all writers: know thyself. What motivates you, what frustrates you, what distracts you. Be aware it can be different things depending on your mood or the task at hand (planning, drafting, writing, editing, ...) and try as many strategies as it's sensible.
Remember, there isn't one right way for all, and there isn't one wrong way for all. Some of best loved strategies for writing are mood killers for me, and some of the most hated ones (in particular, editing while writing) are what keep me writing non-stop.
PS.: If housework distracts you, try to develop a hatred for it. Few things can keep me going at the keyboard as the burning desire to avoid certain house chores. Instant creativity booster.