With a sub-500 score, don't worry about math tricks at this point. Spend the next few weeks drilling your fundamentals until you would feel comfortable teaching a high school algebra class. Without the foundation, tricks are meaningless.
That said... they are also important. So, be sure to spend lots of time working on tricks and shortcuts once you've gotten your fundamentals down.
As for verbal, a great way to cross-train is to add 30 minutes of reading (I recommend the Wall Street Journal) to your daily routine. You'll improve without even realizing it, and you'll be more educated about the business world.
Jim S. - Veritas Prep GMAT Instructor (Los Angeles, CA)