The NYTimes has a short article on a few tips that can save you a lot of money on travel. See it here: Link to NYT Article In brief, here are the keys:
1. If traveling with others, before buying all seats on one ticket, check out price of each individual ticket. If there are lower prices on one or more, buy separately. Otherwise, if you buy all the seats at once, you will pay for each at the highest price seat available.
2. Picking certain days to travel rather than others can reap big savings.
3. Buying ahead but not too far ahead can reap big savings.
4. Checking prices on Tuesdays at 3 pm can reap big savings.