If your travel dates are flexible how should you pick your dates to get the greatest savings? [closed]

When traveling for leisure most people have flexibility in which dates they can choose off before hand and have a priority to travel in the most cost effective means possible. Either to enable them to take a trip which they would not otherwise have been able to take, prolong their trip, or get a higher class of accommodations for the duration of their trip.

When thinking about a trip the majority of people tend to think about things in the order in which they will happen. This typically looks something like:

1. Where do I want to go? (i.e. what attractions/advantages does this location present)
2. How will I get there?
3. Where will I stay once I'm there?
4. What will I do while I'm there?
5. How will I get around in my local city.

A typical approach might be to go to a industry travel website such as Kayak, Hipmunk, Expedia, et. al. and search for air fares to various places deciding and trying varying dates along the way or using the flex date option provided. This will of course give you an idea of the airfare however this is only a chunk of the total cost, albeit a sizable one.

While airfares tend to be far more volatile than say hotel or car rental prices making a decision on dates based on airfare alone could cost you to miss out on other price savings you could have gotten if you had not picked dates based purely on airfare alone. How should you go about determining which dates you should take off?

Are there any applications that exist that make it easy to help tabulate all this data and make a decision based on the entire picture?