Just a few days ago Breaking Bad in its final season won its second Emmy for best drama. The AMC show averaged over nine Emmy nominations per year in its five-year run. And who knows how many ‘water cooler moments’? Here’s one from the season four episode Problem Dog written and directed by Peter Gould.
“One thing I like about our series [Breaking Bad], one thing we strive for is to create ‘water cooler moments.’ That’s certainly not an expression we created, but the way we define a water cooler moment is: Is it a plot development or is it a scene in which people can gather around the water cooler at the office and discuss what the scene meant? Not simply get them talking about it, but have them discuss it and argue over what the scene meant, what it forebodes, perhaps, for the future. And all of this to say that I personally have no particular political or social axe to grind, because I think that stories that set out to do that become kind of didactic or polemic. Stories about characters are always more interesting to me, personally. There is no deeper social indictment at work here, at least not consciously. However, when I speak of water cooler moments, I like for the audience to have the ability to perhaps argue that there are [social or political prerogatives]. I like for people watching our show to have different viewpoints on what exactly the show means. And Walt’s behavior—I like folks being able to argue over his behavior. Is he completely wrong, or is there some rightness to his cause?”
Breaking Bad creator Vince Gilligan
2010 Slant interview by J.C. Frenan
P.S. The last part of that reminds me of the quote by the playwright Ibsen who said it was enough to ask questions. The wrestling with those questions is what people think about after watching a movie, play or Tv show. And if you’re fortunate to strike a nerve it leads to people standing around the water cooler talking it. I don’t know if they had water coolers back Shakespeare day, but I’m pretty sure they had some kind of version of water cooler moments even back in ancient Greece.
Screenwriting from Iowa 
Yes, show me!
It’s been said that there’s no A-B-C method of writing. If there were then every writer would be Vince Gilligan (or insert your favorite writer here _________). But for fun, let’s try. Gilligan explaining that he aims for writing water cooler scenes is A (that could a thematic climax to your story), and since a key ingredient in both drama and comedy is conflict (and then more conflict) let’s call that B, then C is where you capture the magic. How do you capture the magic? This is where I excel—by pointing to others for the answer:
A) “Study the masters”—Director Martin Scorsese
B) “How did I learn screenwriting? Endless hours at the typewriter, then the computer, which came along later. It was really a lot of applied time and effort and self-study. Which is the way most people learn.”—Screenwriter Frank Darabont
C) “I never took a (screenwriting) course, what I did was read every screenplay I could get my hands on. And I tell people go find the crappy screenplays because they are abundant man. And that was what my inspiration was to a degree. So I wrote 12 screenplays before I gave one to anybody.”—Screenwriter Sheldon Turner
Short answer; read a lot, study movies, and write a lot.