I often see people barge in without intro, without establishing rapport, without awareness.
This will improve your affinity and flow with others:
Look at a person before you talk to them. Acknowledge their existence. Get a sense of who they are, their current mood and situation. THEN and only then say what you’re going to say.
Before I order in a restaurant, I take a few moments to acknowledge the waiter. Before I reply online, I check who I am talking to. Before I tell my wife a story of what happened today, I check to see if she’s in an available state. Before I address a group of students in a seminar I take a moment to look at them and assess their state.
Real communication means to first synchronize with another person. Then, whatever you say, will be received.