I usually have no problem hopping from one world/character/story to another, even mid-writing, because it seems like my brain is usually multi-tasking stories. I'll be working on dialogue for one and a character completely unrelated to the fandom will pipe up to be heard, and I'll like it so I have to take that and run with it in a different story and completely jump into something else

*shakes head* Wow, I can only stand in awe of your ability to tame the chaos! It certainly explains how you can create such interesting crossovers (at the drop of a hat? :P). My fandoms rarely mix in my head, though I did have a very weird twinge for a kinda GH-inspired KI fic (LOLWAT) o.O

But yeah, for me, it can be little as one episode (I began drabbling in Dollhouse after the second, even if I never posted anything).

I guess I find this fascinating, because in general you receive so little information in a pilot, or first regular-season episode. And, well, I feel like why should I be writing derivative fiction when I haven't even seen what the creator does with it? :P I guess I need a pattern of behavior, first and foremost.

This has been a very interesting discussion. Its fun to get a peek inside other folks' writing processes!