When I'm around JWs and they start their "we are in the last days" talk I just act as if I did not even hear it. I only respond to their non-preaching statements.
When dealing with shunning, I always ensure they must be proactive in their shunning. I will not tip-toe around them. I'll walk up and talk to them like any other normal person. If they want to shun me, they will have to do it overtly and intentionally.