One of the things I have noticed about writing is that I usually don't love my first draft. I like things about it, which become the "meat" of the book - but for the most part I plow through it to get words on the page. Where I really start enjoying a book I've written is in revisions. That's where I can dig into the exciting parts and expand them.
As Nora Roberts says, you can fix a bad page, but not a blank one. It's best to get those words down first, and then worry about rearranging them. You can't sell a book if you haven't written one, after all.
It is hard for me, Type A personality that I am, to muzzle that internal editor enough to stop worrying about the words so much the first time around, and just let them be. I have found, though, that with practice it gets easier. I notice too that having written a synopsis prior to writing a book, while easier, tends to "spoil" the book for me. The answer to that is not to take your synopsis too seriously. The major plot points should not change, but you can deviate while writing the book if a good idea hits you. It's like they say in "Pirates of the Caribbean" - it's more of a guideline. Just write it - and then worry about polishing the details. :)