hi there!!! I must say I love your username!!!!!! EATINGELEPHANTS is so so so nice!!!!!
I have to be honest with you; everytime I say or plan to do something in the evening once I get home, I almost always NEVER do it. So the best thing to do is to make the most out of the working time I have in the morning or afternoon.
For example, if I haven't done anything in the morning, I make sure I do something in the afternoon. Or if I haven't worked all day then I will try to do something in the evening (when I get home!) and about 80% of the time, I do this, because my brain or body remembers it hasn't exactly worked yet in the day.
as for writing articles/journals, just take it as part of the phd because then the article(s) become chapter(s) so then after putting together the pieces of the jigsaw puzzle, you'll get a complete piece in good time :-)
I teach once a week; and if I am teaching and I try to do my phd work I find that I cannot completely "separate" myself from each; for example rushing back from the lab I would have to "adjust" myself back into phd mode and sometimes its just not possible. So on my teaching day, I do my teaching and after that, next day, go back into Phd mode. For me, that seems better. I am also able to concentrate better.
As for volunteer work, I don't do any now. I also used to have a part time job with the local council, but it was taking too much of me, and I had to give that up.
About having a life, I would say, life goes on, phd or not. So I try to fit it in around; but maybe this is easier for me in the sense that I like being alone, I hardly go out; I like my own space; so I don't find myself missing out on hanging out with friends etc. I think we just have to work around fitting in our phd into our life, well something like that. I may not be the best person to talk about this :p
anyway, that said I think you'll be ok.
love satchi
