Theatre cannot compete with the naturalistic realism of movies and t.v. Rather live theatre's power lies in ritual and imagination.
Comedy and tragedy are best mixed. Usually.
I am impatient with formulas, which do seem like sometimes extremely useful tools with which to play (never forget that is what I am writing--plays not works). But slavishly following same stifles creativity.
One of the most powerful of all things I have ever experienced as an audience member--and I seek to create in my own plays--is that moment when I look at a character and see myself. I call it a "Hello Me" moment, which is probably too silly for the gravitas I think implied--which is itself a good reason to call it that.
I see four aspects in theatrical storytelling, which I call PACT. Plot, Atmosphere, Character, Theme. Me, while I try to have exciting and surprising plots, I am far more focussed on the other three.
Also, I am a collaborator. Playwrights of necessity must be. So I try very hard to help the actors, designers, directors who will one day breathe life into my writing. This includes leaving room for them to make their own artistic choices.