Actually... the real helpful tip if you don't want to be forced to a new thread, is no unnecessary abuse reports. Posting on the big threads doesn't slow the server down, but ~moderating~ them does. I think basically, for the mods to come in and delete posts, they have to load the whole thread.
We were minding our business on the Idol thread, then late one Saturday night, when hardly anyone was around, the mods said the thread was straining the server and we had to start a new one.
This was the same day that FR was down for 5 or 6 hours--I don't know if that had anything to do with it.