Voluntary tutoring - this was mostly through people I knew within my (cultural) community who had a tonne of connections. I think the best place to start (as it was in my case) was just writing to people in media (newspapers/magazines) and talking to them about what you want to do.
Nursing homes - I had an aunty who used to be pretty high up in the ranks at one
Soup kitchen (just chucked this one in bc it came to mind) but I also did a spot of volunteering at Westmead Childrens - my sister was a long term patient for a while and I got to know the ward staff and her surgeons well which helped out.
I think it was just a matter of luck and knowing the right people, but the best thing to do is write/see people in person. Always seems to get more responses than emails/telephone.