Be flexible with dates. By doing so, airfares and accommodation prices can vary enormously. My Dad found on one occasion when booking an airfare found that the same fare was $1495 one day and $3050 the next. The difference? School holidays!
When I book flights I always try to use the tools that let me see fares over a week. For example: kayak.com allows you to search for airfares three days before and three days after a selected date.