A common writing bugbear of ours, here at the Red Lounge, involves joining two actions together using the words 'as' and 'while'. People who do it, do it a lot, and after a while, it gets boring.
“I am the king of this castle,” he bellowed while slamming his fists down on the table.
He began to stammer a reply as he slowed to a walk.
In both sentences, the 'as' and the 'while' slow the action down. Honestly? They aren't needed. This is what I'd do:
"I am the king of this castle." He slammed his fists down on the table.
Slowing to a walk, he began to stammer a reply.
There's more strength, and better pacing in both sentences now.
"But this is correct," I hear you say. "Everyone does this. My Grade 5 English teacher would approve." This may be so, but it's still not great writing. And I know you want to be better than this.
This is where it's important to read a lot, but not just anything. Read smart, clever, well-written stuff that goes beyond the pedestrian writing that's so easy to find out there in book-land. You'll write better if you read better.
Go look for great constructions and contrasts, recognise them, analyse them, and then use them yourself.