I incorporated right away so that I could write off big chunks of my day-to-day expenses. I write off a big chunk of my rent and most of my meals that I go out to eat.
Of course, depending on what you try to write off, the IRS might be very suspicious -- but that's true for corps, too. The rules about what constitutes a "business expense" still apply to corporations.
It does make the bookkeeping easier to have a corporation, and it may affect the odds of being audited, depending on exactly what your profits and expenses are. Again, there is no cheap substitute for a real accountant's advice.