I'm trying to pick a good selection of characters in mine. All of them are Laura-focused, but I figure if I pick one Laura/Bill and one Laura/Lee and one Laura/Kara, or whatever, then my remixer can write whatever their preference is in terms of pairings. So maybe pick three that have a variety of different characters?

The other thing I'd suggest is that shorter fics are generally easier to remix than longer ones, I think, because there is less that you have to try to take into account in your remix.

Hope that might be a bit of help :)