Today is the halfway point in the arduous journey that is NaNoWriMo 2013. I've just typed by 26,962nd word, just shy of the 54% completion mark. It's incredible to look back at what I've written so far, just over a hundred double-spaced pages in fifteen days.
What have I learned so far?
Trust your instincts. Go off in different directions that you intended and see what happens. You might end up scrapping it, but don't dismiss the idea.
Don't be afraid to write the scene again from a different angle. Ideally keep going on forging ahead, but if you've left behind a scene that just doesn't feel right, spend some time rewriting it, try it from a different person or POV. Play around, explore it, you'll be pleasantly surprised at what you might discover.
Don't get discouraged. By now, a lot of my original ideas have been written on and it's that 2/3 part of the novel that's difficult to get down. It's hard work, but keep at it.Sometimes the flow will just take you, and other times, you'll be checking your word count every 50 words!
And here's a great little NaNoWriMo pep talk by Neil Gaiman, who knows a few things about writing novels... http://nanowrimo.org/pep-talks/neil-gaiman
Keep up the great writing!