I'm addicted to character creation, but I also believe in well-rounded individuals. I try to put a little of everything into the characters I create; I try not to be redundant with personality and appearance, and I always try to give my characters some sort of "purpose" to them. This purpose could be a plot, or sometimes I just want to prove a point or add some spice in the mix (IE Calvariam, an older character). Asking the hypothetical questions is a helpful tool-- you ask the same question for every character and determine how they would react. The goal is for every character to react differently.
Setting could also be a muse-stroker or a complete buzz kill. I lost TONS of muse for my character Safenger after he sat inactive and the Helovian setting shifted around him; the Veins became silent, and Catillatio started stalking the land, which was a role I was originally planning for Saf himself. I started channeling his personality through other characters as well, so he became pretty redundant. Maybe I can find a use for him later, but in terms of inspiration he has died in my mind.
Music is a big big BIG plus when it comes to writing posts. Assigning different songs/artists for different characters is also a good way to get into the mind of that individual. So far, I've broken it down to these categories:
ZIKAR-SIN is inspired by BEN FOLDS and TYCHO
CIRCE is inspired by COLDPLAY
LAILA is inspired by J-POP, K-POP, and anything bouncy/bubbly
BERNADETTE is inspired by JOE HISAISHI (composer for many Miyazaki films)
And so on :3 I also mix and match when the setting calls for different emotions.
Before I even start a post, I simmer over it in my head during the day, while I work or when I'm taking notes in class/doodling. I contemplate the general plot or the events in the thread, and I try to create a reaction that flows seamlessly with the goings-on. The longer I stop thinking about a thread, the worse the flowing is-- although if I don't immediately respond to one, it doesn't mean I'm not contemplating it. I try to take my time when I reply, as I've found impulsive ideas tend to be unfinished things that fizzle out in the end.
Once I figure out the appropriate way to respond to a thread, I break my "hypothetical" response into sections, giving the classic sequence of literary plot (introduction, rising action, climax, denoument). I place labels there for general idea, and when I finally sit down to write the post, I go back to those original ideas and flesh them out as I type. Sometimes truly epic quotes come to mind as I'm doing this-- other times, I find some sort of parallel in literature I've read before, and I either quote that particular lit or funnel inspiration from it.
So...read, kids :D
Finally, the most important thing I try to emphasize is that this is not the most important thing in the world to me. I have other things to do, and this is a surprisingly refreshing way to keep creative juices flowing and keep me occupied and happy. Channeling passion INTO something is different than being IMPASSIONED by it; when I start getting too 'into' it, I know I need to step back and take a breather. I'm not too bothered with word count, either; I feel that a 250 word post is just as good as a 800 word post, as long as the general point comes across and there's enough material to respond to. I also try not to be intimidated by other, inevitably better writers than myself; instead of thinking "WOW, I wish I can write like that!" I try to think "WOW, let me try to write like that!". It doesn't show, however, because I *obviously* have a problem with being long-winded. ^^;
You're awesome if you took the time to read all this XD I didn't mean to type all this but there it is! I guess the main points I want to emphasize is that I like to KNOW my character, HAVE FUN writing, DON'T STRESS it, and just DO IT :3