Currently, to make a skin, the process is like any other extension: fork Example skin, rejig to do what you want (and write your own styles and stuff, since it is a skin). This is good in that it allows for all manner of flexibility, but not so good in that a lot of that flexibility needs to be actively used even for trivial/common things due to a lack of existing functions in core. There's just not much there for folks to simply reuse without having to reimplement the kitchen sink by hand because it's all centred around MonoBook and Vector and that's it.
Jon Robson has been working on a thing to provide a markdown abstraction layer for skin development, which is a very interesting step forward that was largely lost on me because I don't understand markdown, but we do need something like this so that people don't need to deal with the underlying framework if they don't want to just to make what should really be a very straight-forward type of extension. (That was Jon, right?)
But we also need a better underlying framework to begin with, not in the least so the stuff on top can work properly.
Let's talk about this. Let's come up with something actionable. Let's be the heroes MediaWiki deserves, even if it doesn't technically need us. (After all, people fork Vector all the time, and it sort of works! It doesn't work very// well//, but they still do it.)