you should get into the habit of just hello and see where conversation leads. Out of habit most will respond with a hello in return and if they don't they nothing ventured nothing gained.
Exactly. At first, take small baby steps. Then take larger steps.
Another trick is to go to a store (Safeway, Lucky's, Kroger, WinnDixie etc..) where they wear name tags. As you walk up, the cashier will greet you with some contrived/mundane greeting- "How are you today sir?" and most people say 'Fine' and that's that. Like they really give a fuck how you're doing, nor do you care what they are asking for?
Instead, try responding back with their name..."I'm good today Roger, what's the good word today my man?" Something a little bit more energetic than their level. Or "Hey Teresa, the world is a horrible place, but probably could be even worse if....<insert sarcastic remark and SMILE>." You'll be amazed at how different the reaction can be. Sometimes you'll end up talking to them for a good while, unless there's people behind you.
Another funny one thing to attempt....call a random person in the phone book...ask them what is the latest movie they've seen, or recommend. You could say "This is Domino's Pizza, how my I take your order?"