I love the quote by some famous woman writer (whose name I can't remember) who said, "I try to always leave out the parts that people skip." To me, that applies to lengthy descriptions of nature, or clothes, buildings, etc. I can appreciate those things read in other contexts, but when I'm in the middle story I just want to get to what happens next. Other people may have other things that they always skip over in books, but I think it's a good rule to remember when you're writing. There's no point in spending time on things no one wants to read anyway.