I've been working from home for 11 years and that's the entire time I've been a GTD-er. I've tried about every configuration of contexts you can dream up--by energy level, by amount of time I have available, etc. What works best for me is to drop the "Office" context and split a few (like @Computer) out into business and personal and sometimes I break it down by software program too. Other than that, I use the basic contexts Kelly has recommended. I also have "Waiting for" (my favorite!) and, if it gets unwieldy, I split that between business and personal too.