When planning a trip, typically the largest single expense is the cost of lodging. While there are newer options available like Airbnb, many prefer the convenience and familiarity of a classic hotel chain.
While I would not suggest this approach in every situation, if you are planning a spontaneous trip I would do the following:
Step 1: Spending to save is an option that families with children can truly benefit from. For example, always select hotels with a free breakfast when possible. Typically the price is still reasonable and you will save $25-$35 to feed a family of four breakfast. Selecting a hotel with a pool is also a great entertainment option to prevent unnecessary expenditures in the evening.
Step 2: Locate your hotel either during the off season when they are desperate to book or last minute when they are offering deep discounts to fill rooms. Utilize Expedia, Kayak, or Booking to locate hotels with your preferences, room availability, and price range.
Step 3: After finding the perfect hotel in a desirable price range, go to the hotel website, find the phone number, and book through the front desk. You will always get a better price going direct because hotel chains pay fees close to 10% to outside vendors who book through their sites.
As stated, while there are many ways to spend money while on vacation, paying extra fees while booking a hotel room should not be one of them.