Ah, the dreaded subject. I've been meaning to write about this for awhile, but I just haven't been able to get started. Hurr hurr.
Writer's block affects us all, even, I would assume, writers as prolific as James Patterson, Fern Michaels and Nora Roberts. So what do you do when you simply can't seem to get the words in your brain to line up neatly on the page? You have several options.
1) Walk away. Give up. After all, there are a LOT of struggling writers out there, all trying to break into the same field as you. Why bother fighting it when the odds are you're just going to fail anyway?
However, if you don't subscribe to the Lemony Snicket version of pep talks, let's look at some more ideas.
2) Just sit down and WRITE. Don't worry that what you're writing isn't fit for lining the bottom of your parakeet's cage, because that's what got you blocked in the first place. Just ignore the inevitable mediocrity at the beginning, grit your teeth and Keep.Going. This is basically the philosophy of NaNoWriMo. Sure, they say, you're going to get a lot of coal, but sometimes you'll find a diamond in there as well.
3) If the head-on approach doesn't work for you (and if we're being honest, it often doesn't for me) then try an oblique angle. Can't figure out the next scene of your book? Set it aside for another day and pick another scene out of your head. Is your heroine marooned in the sewers of San Antonio with pursuers hot on her trail and no clear way to escape? Leave her there to consider her wrongdoings and concentrate on a completely unrelated scene. You'd be surprised at how often that completely unrelated scene suddenly becomes connected to the one that you got stuck on and presto! You have a way out of the sewers and your heroine is duly chastened and ready to listen to your directions. (Well...it's a good theory, the whole "chastened" thing, anyway.)
The best way to avoid writer's block is to get yourself into the habit of writing every day, for a set amount of time. No days off; this is not a 9-5 job you've gotten yourself into. If you're serious about this, you must be willing to work every single day with diligence and persistence. Oh sure, a day off here and there isn't going to hurt you or your novel, but let that be the exception and not the rule.
Whatever approach you choose, don't give up. Keep slogging away, even when it feels hopeless. I promise, it will eventually pay off. Maybe not for months or even years, but eventually, it will.