Last issue, I gave some thoughts on the general process of a Featured article candidate review. Today I'm going to take a deeper dive into some specific problems which came up at FAC. This won't make a lot of sense if you haven't already read part 1 to get the context.
I'll start with a couple of things that got left out of part 1. One of the unusual bits of FAC culture is that it's totally acceptable to solicit reviews. You could ask on other users' talk pages, or a wikiproject talk page. Another thought is that when you think your article is ready for FA, walk away from it for a few weeks. Once you've read something 100 times, you're burned out and taking a long break will often let you see things you glossed over before.
I also strongly suggest you get your article to WP:GA first; every time you get somebody else to read your stuff and tell you which parts of it suck, the end result is a better article. Also, if you don't bag a GA on the way to FA, you won't be eligible for WP:FOUR.