2. Sticking to U.S. travel sites
Major U.S. domestic sites like Expedia, Travelocity, Orbitz, or Kayak are fine. Booking your vacation through one of these websites is easy and simple. You remember William Shatner recommended one of 'em; search, find, pay, and you’re done. But they don’t search all companies around the world and, by using only them, you’ll miss out on airlines, hotels, and deals that don’t show up in U.S. based searching.
What you should do: Expand your horizons to include websites such as Skyscanner, Momondo, Holiday Pirates, Laterooms (hotels), and Agoda (hotels). This way you’ll get a more thorough view of all the deals out there. Sadly, at this time William Shatner does not endorse any of these, FYI.