As it relates to how my plugins look, my new approach (for the ones I’m getting ready to release shortly) is to make them look decent out of the box, in the default WordPress 2.0 theme, and then just add enough in the way of IDs and class names to make it as easy as possible for people to customize if they aren’t using the default theme.
My thinking on this is that I don’t really think there’s any good way to provide for many complicated style rules out of the box without making it more difficult to customize when the user does want to use an alternate theme. So, what I think the best approach might be is to make it OK (without much or any CSS) for people who are totally uncomfortable messing with their themes, and then for those who ARE into that, they may have to tweak it a little bit to make it fit, but they will have to do that on everything; that’s just part of choosing a different theme.
What do you guys think?