But Consumer Reports' Tod Marks says these days a good place to start is with the hotel's website.
"Hotels have taken back the night by imposing best-rate guarantees. That is, find an advertised price lower anywhere else and we'll match it plus give you a bonus," said Marks.
So book at the hotel site, then keep looking online for a cheaper rate. It also pays to look for special deals on hotel sites like up to 20 percent off and complimentary parking.
"Now if you really want to save and get the rock-bottom drop dead low rate, do what I do. Use Hotwire, Priceline's Name Your Own Price program, or use Travelocity's Top Secret Hotels. They don't reveal the name of the hotel until after you've committed to purchasing that room for a given night," said Marks.
However, it can lead to big bargains. On Hotwire, Marks booked a room at what turned out to be The James, a high-end hotel in Chicago. The rate was $133 a night. The best rate the hotel or any other site offered was $234.
While budget hotels are the cheapest place to stay, Consumer Reports says some are no bargain. Its survey of almost 23,000 subscribers found America's Best Value Inn is among the worst. A much better bet, top-rated Microtel Inn and Suites, where rooms can go for as little as $59.
"They offer decent upkeep, they're clean, and check-in, most of the time, it's a snap," said Marks.
Consumer Reports says if you can't plan ahead and need to book a hotel for the same night, there are still ways to save. A free app for smartphones called Hotel Tonight shows deals on hotels in some 30 cities.