I'm noticing a trend so figured I'd share something I've found effective to just get the ball rolling from a very non social place to getting into a social mindset.

From now on, every time you interact with a cashier/server/salesperson etc, ask them how their day's going. No pressure for anything after that, if they just say 'its good' then just say that's awesome and go on about your day. If they give you more or ask about yours feel free to play with it more and converse (but don't be a total autist and get into a 5+ minute convo if she/he's busy or people are waiting). It's a good habit to get into that will make strangers less intimidating.