You see ads for them all the time - last minute travel deals for a quick getaway, and it's a total steal. Or is it? In my experience, you'll save more money and get better deals...
... if you plan ahead of time. This definitely applies to flights and car rentals. I can't stress this enough. If you wait until the last minute to book a flight or car rental, it'll wind up being way more expensive. I've discovered this the hard way. Book as far in advance as possible.
The other nice thing about planning in advance is you get the benefit of anticipation time, as well as an opportunity to plan and research the best places to go.
Much of a vacation value comes from the excitement of taking a trip. And you'll enjoy your vacation more if you have time to research the destination and plan accordingly.