The trick to keeping the fight's paces is to keep us all on our toes by using what happened in the last post to frame your post. The way for instance my character is down and out right now, but Hwo and Engar both mentioned him in their posts, and what is happening to him...it adds to the overall story.
Actually--and this observation ought to make Cuc give me a nod--it's a lot like a wrestling match, behind the scenes. We PM one another sometimes with ideas for what we're going to with our next posts, and we always run the idea by Cuc. Though it seems like we are fighting, it's a matter of cooperation. Technically I'd consider us a writing team working on a project together, more than three dudes trying to "outperform" one another.
I guess we just know how to entertain a crowd.
The trick though, as I said, is to use what happens in the other posts to help flesh out yours. Our characters didn't all start as behemoths, either--when Engar came in his first couple of posts demonstrated his power, so we had to come up with a way to match it. I can tell you that my transformation to the catalyst version of Pride wasn't planned or even wanted at all. But you roll with the punches.
Technically, if you know what you're doing well enough, you could write a post where you do almost nothing but dodge us and make us hit each other FOR you, if your character's that weak.
Just remember one thing: if you're going to have a character do something and you're not sure they'd actually behave that way, PM the person and ask.