We've been actively working to reverse this, getting to know lots of our neighbors. One thing that splits the difference in terms of planning pain was backyard fires. We like to relax around the fire anyway (even summer nights are cold in the high desert) and we just send out a casual "fire night" message to our friends list. We have snacks and drinks on hand, and people show up or they don't. My wife's east coast and was missing her "stoop-sits" from Philly, and this is our west coast variant.