I talk to strangers; start a conversation with the clerk at the store? Just ask when they get off or tell them about the weather outside (large grocery stores without windows are good for this :-) or if you overhear the clerk and person in front of you talking about something, look at them and smile/laugh at something funny one of them says, etc. You won't see them again or be "recognized" if you do and it is an easy way to get a little comfortable realizing that what you say does not have to be earth shattering or very clever but just friendly and that people are more than happy to be friendly toward you.