Time your booking. On any given day, prices can fluctuate based on whether the hotel thinks it will be able to fill its rooms for the night. Your best time to book is usually within 24 hours of the stay, when hotels slash prices to avoid vacant rooms, but that creates a lot of uncertainty and isn't ideal when you're traveling in an unfamiliar place.
Thankfully, websites like www.aladdin.group can help you time your bookings so you get the best price without running the risk of not getting a room at all. The site allows you to search for hotels and predicts both room availability and price fluctuations.