Keep everything in context, and try to have each line doing more than one thing - not just giving exposition but also revealing character and history, etc.
Sentiment: POSITIVE
I would fix other people's lines if they asked me on occasion. The hard part of writing is the architecture of it, getting the story and structuring it. Not the tweaking of lines.
Exposition has legitimate uses. It's the most efficient way to summarize background information, including necessary information about a character's history. It can set the stage well for a major dramatized event.
With comedy, don't try to be funny. That's really helped me. Just say the lines as you would say them, interact with other characters, and try to make it as real as possible. It will come out funny.
You can't just sit there and do the lines. You have to do something revealing or unusual.
You can't tell any kind of a story without having some kind of a theme, something to say between the lines.
I'm just always learning lines. I've learned to flag the really crucial scenes, and I start figuring them out and committing them to memory as soon as I get them.
Concentrate your narrative energy on the point of change. This is especially important for historical fiction. When your character is new to a place, or things alter around them, that's the point to step back and fill in the details of their world.
A terrific exercise is to take a paragraph of someone's writing who has a really strong style, and using their structure, substitute your own words for theirs, and see how they achieved their effects.
As with anything, you need to keep your creative juices flowing and keep the character interesting.
For each detail I include, I throw dozens away. So I guess the first trick is to pick the right details, the most revealing details. Then I think one must simply write quick, clean, bright prose. For me, this means rewriting and rewriting: almost never adding, almost always cutting.