The holiday shopping season is a great time to upgrade your bed for less, thanks to the Black Friday mattress sales. But with so many offers, it can be hard to spot the bargains. That's why we've compiled our expert shopping tips.

The best mattress brands have launched sales with great deals on memory foam and hybrid models. There are five key signs to help you decide if the offer you're looking at is worth jumping on.

Before we get into our expert tips and reveal these key signs, here are some of the biggest mattress offers we've seen so far:

Keep in mind that mattress prices naturally fluctuate throughout the year. For example, Black Friday is typically when you can find the cheapest prices, while summer months tend to be more expensive.

So if you see a mattress being offered at a deep discount, take the time to examine its price history, although for models sold on Amazon, you can use price history sites like CamelCamelCamel or Keepa, For products sold outside of Amazon, these are not available.

In that case, use our dedicated mattress information page (see below). Not only will you find the latest discounts offered by the brand, but you will also get an overview of previous sales the brand has had this year. This will give you an idea of how good the current offer is:

One of the nice things about buying online is that it is easy to find good deals. While the discounts you see on a retailer's site may seem attractive, the mattress you choose may be cheaper on the manufacturer's own site.

For example, this Black Friday, PlushBeds is offering a $1,250 discount and up to $549 in free gifts on mattress purchases. No third-party retailer has yet to match this largesse. Sleep Number is also offering 50% off its 360 iLE SmartBed for up to $3,449.50.

The reverse is also true; don't assume that the discount offered by the manufacturer is the lowest price. For example, on Amazon, Mattress Man, and Mattress Firm, we saw several early bird discounts on brands like Tuft & Needle and Tempur-Pedic.

If you're looking for a new bed or accessories, take a look at the expert guides below. Below each item, our price-tracking software will show you today's lowest price:

We often see mattresses bundled with free gifts such as bedding (usually pillows, sheets, and mattress protectors).

It doesn't always mean free bedding. Nectar, for example, gives away bedding and a Google Nest Hub 2nd Gen (with sleep sensing) with the purchase of a Nectar Premier or Premier Copper Mattress.

Quite a few manufacturers also offer discounts or free gifts. In the US, Dreamcloud is offering $200 off a mattress plus $399 in free gifts, and Awara is offering $200 off and up to $499 in free bedding.

Getting a good night's sleep is essential to good health, so finding the right mattress for your needs is important. Most brands offer a risk-free trial period during which customers can properly try out their new bed. If you change your mind during the trial period, you can return the mattress for a refund.

Trial periods vary by brand. It takes at least 30 nights for your body to get used to the new mattress. The average trial period is 100 nights, but some companies, such as Avocado Green and DreamCloud, offer a one-year trial.

To receive a refund, the mattress must be kept clean.

If you find that a mattress is not right for you, the last thing you want is to have to go through the hassle of returning it. Always check the return policy before you buy, just in case.

Most bed-in-a-box brands offer clear return policies, and some offer free returns. Some, however, charge a fee, so read the small print first.

Finally, find out what kind of warranty is offered: 10 years is the average, but some companies, such as Nectar and Dreamcloud, offer lifetime warranties. For more information, read our feature on how mattress warranties work.