Warnings are a whole different kettle of fish and I don't want to get into that endless debate, but what about headers? What do you put into your header? What do you want to see in others' headers?
I like to put the usual: title, pairings/characters, rating, warnings, spoilers, summary, disclaimer and author's notes. I also like word count. Why? Because sometimes I want a long, juicy read and other times I don't have time. I need to know if I'm going to be reading a bite-sized drabble or a Big Bang-length novel.
I do like the method you can use for hiding warnings and other info. For example, if I have a twist pairing, I can hide it and the reader can click on it to find out! Otherwise I list everybody! ;)