Next to flights, hotels are typically the most expensive part of a trip. While flights are getting harder and harder to save money on hotels are a bit easier. If you don't have time to book at least a year out then there are other ways that can help you save if you have a bit of time to hunt.
Book the Type of Hotel Based on your Days
When you are going to book a hotel, the day of the week you are travelling can make a difference on the price. Business hotels are usually slow during the weekends and the summer time or over holidays whereas resorts will be busier during the Business hotel slow times as those are usually when families are travelling. Business hotels can also have additional amenities that standard hotels don't offer (free printing, wine hour, free Wi-Fi, etc) which can help you save money if they are something you'll use.
Ask for a Corner Room
While you can ask for a free upgrade or a larger room, a lot of rooms are roughly around the same size but if you ask for a comer room then these are typically larger than their average square footage, quieter, and may have more windows.
Check in Late
If you check in later in the day then you are more likely to get a free upgrade as they will have known who has checked in and what rooms are available. Just remember to check with the hotel as to what the check in period is or alert them you are arriving late as some have limited check in times.
Ask for an Upgrade / Let them Know of a Special Occasion
Call the hotel directly (not at the 1-800 number) and ask them for a free upgrade as the hotel should know what their availability is at that time. It's also important to call the hotel directly as they have more flexibility than the general call center agents. If the hotel does say they are full, do not try an pressure them to give you a hidden room.
This used to drive me nuts! Yes, we do have "hidden" rooms but these rooms are usually not rented for a variety of reasons from painting to it's monthly cleaning, broken items to a breathing period (someone died) and more. If a hotel is wanting to rent these rooms, they will as having these rooms off the market causes them to lose money.
If you are going to the hotel to celebrate a birthday, anniversary, etc let the hotel know. They might upgrade you or even give you a piece of cake in your room, something is better than nothing. If you are travelling for a funeral, ask the hotel if they have funeral rates as some chains do give discounted rates or will put you in a quieter area of the hotel.
Full Pre-pay
Book a full pre-pay, non-refundable room if you know for sure you are going. Booking within the cancellation policy will also save you money but again, it will be non-refundable.
Bundle Flights & Hotel
All inclusive packages have been doing this for years but some websites like Expedia are starting to catch on. The general idea is if you book your flight with a hotel then you'll save money on one or the other (most of the time you won't know which).
Loyalty Points
Sign up for the hotel's loyalty / rewards program before booking. This could get you things like free Wi-Fi and also increases your chances of getting free upgrades as the hotel knows that you want to stay there. If you can earn points then you can also use these towards things like free rooms or discounts. Check the program but sometimes they will give you additional perks if you refer a friend or you book specific things from certain car rental companies to room types.
Sign up for Newsletters
If you want to be the first to know of deals, sign up for their email blasts and keep an eye on them for deals that might work for your trip. Make sure to read the fine print however so you know what you need to do to get it as well as if you can cancel. A lot of deals are known to give you 25% off for example but the first nights deposit will be taken at time of booking and is non-refundable.
Hotel.com Hotel Price Index
Just like flights, some websites are starting to "predict" when prices will go up / down for certain areas / time periods. Every little bit helps so why not take a look before you go.
Download the App
Some hotels have their own apps but there are lots of apps for expedia, hotel.com, tripadvisor, and more that sometimes give deals that are only accessible on the app. These consortium websites may also have secret hotels that you can book to save money. Secret Hotels will give you the price and the general area of the hotel but you won't know the name of the hotel or the star level until after you've booked it.
Stay at a New Property
Freshly opened hotels usually offer discounted rates to get people through their doors so while you might not know what you are getting it will save you some cash.
Use Coupons
While physical coupons might not exist, check out online for coupon codes or see if there are newsletters / websites that you can sign up for discount coupon codes. This can take a bit of hunting and might not be worth it in the long run but if you have the time and you are determined, it might be worthwhile for you.
Check your Credit Card Perks
Some credit cards have additional perks like free upgrades or discounts on certain chains depending on the type of card you have so check your inclusions to see if they have any.
Last but not least, this is not a way to save money before you go but can help during your stay.
Let the Hotel Know of any Issues during your Stay
AC broken? Neighbors too loud? Dirty bedding? Let the front desk know while you are still onsite. That allows the hotel to correct the issue to your satisfaction. If you don't complain until after you've left it makes it extremely difficult to get any refunds or discounts on your stay as the hotel was not given the chance to fix it and can feel that you are trying to scam them since if it was bad then you would have reported it during your stay. If you have booked via a travel agent or a consortium, reach out to them during your stay as well if you have issues and the hotel is not assisting you.