Find something you enjoy doing, and you will undoubtedly meet some women who share your interests and will be suitable for a relationship.
The idea of small talk by the checkout counter is OK, but in my personal opinion, I'm often in a rush, so I don't really want to be chatted up at that point ( not that it ever happens to me) I also would not give my phone number to someone I've met for all of 2 1/2 seconds.
Volunteering is something I reccommend to people to meet others, not only do you get a good feeling from being a do-gooder, but you also can meet some interesting people who share your interests. Find an opportunity in your area that would allow you do something that interests you -- (
www.volunteermatch.com - has a lot of excellent opportunities, some one time only committments, some a lot longer)
Take a course that interests you, and there will probably be some women in the class that interest you.