“This is a brand new post,” he said.
She said, “Why are you posting this?”
He said, “What do you mean? This is my blog.”
She said, “So, cant’ you write it better?”

All too often we get into the rut of “he said, she said” as new authors. It is easy to do and after all we are only trying to clarify, to the reader, who is speaking. (As if they can’t figure it out.)
During the course of writing my first novel, I purchased many books on the craft of writing hoping to glean tidbits here and there that would improve my story. Some did, some didn’t. Again, my editor and actually I should say my mentor came to the rescue. She pointed out various ways of presenting dialogue without the “he said, she said” scenario. So let’s try the opening again.

Robert blurted, “This is a brand new post.”
“Why are you posting this?” Sally replied, wrinkling her freckled brow.
“What do you mean, Sally?” Robert’s face crimson with anger. “This is my blog.”
“Can’t you write it better?” Sally said quietly, wishing she hadn’t angered her brother.

Now I am introducing not only dialogue but action into the dialogue. It get’s the point across, as did the opening, and reflects the tension between Robert and Sally. Along with showing and telling, I can’t tell you how many scenes I was “suggested” to re-write – showing and not telling – and showing with emotion. It does make the scene richer. There are also many opportunities, when there are only two people in conversation, that nothing but dialogue needs to be written unless you are trying to convey action.
Stay thirsty my friend.