Interesting. @Wolfe: Care to explain that? Does that mean get as many borders as you can, or get borders at specific times, or...
Timing them so that you get borders at times when you can hit a lot of enemies, or hit a boss accurately for an extended period of time.
Also, typically you'll want to be unfocused while having borders, as that greatly increases your border bonus for most characters.
The wiki actually has a pretty handy scoring guide for PCB. I'd try to summarize it, but I'm not that great at PCB, and it's system is relatively complex.http://touhou.wikia.com/wiki/Perfect_Cherry_Blossom/Gameplay