Planning on buying in this year's Black Friday sales? Then we can help to make sure you're prepared. Not all the deals fighting for your attention will be as good as they seem, so make sure you know what to watch out for before you part with your money.
Unclear discounts and near-on constant sales are just two examples of issues our experts have spotted that could trick you to thinking you've got a worthwhile deal. But it's not just pricing that matters - if the product's no good, you're not getting a good bargain.
Mattresses are very popular on Black Friday. Last year, we uncovered deals from Casper and Dreams, plus a 36% off promotion on the . However, you might find even better discounts if you're willing to wait.
Our mattress expert says:
'If Black Friday rolls around and you're not quite ready to invest in a new mattress, don't panic. We see popular mattresses go on sale all year round. In fact, we've seen discounts up to as much as 45% for an Emma mattress and even 60% for a Dormeo at other times of the year.
'If you do spot a deal you can't pass up, then make sure you check the terms and conditions for any sleep trials and find out how long you have to use your mattress before you can return it.'
Lisa Galliers, Which? mattress expert
Bigger isn't always better. According to our annual sound bar reliability survey, plenty of shoppers buy a sound bar without realising how big it is, or end up choosing a model that's the wrong size for their room.
Our sound bar expert says:
'Most sound bars have an additional speaker called a subwoofer, which is designed to produce extra bass. This is often built into the sound bar, but some models have one or two external subwoofer speakers which are about the same size as a bookshelf speaker.
'It's important to opt for a model that's not only suitable for the size of your TV, but also the space you have around it.'
Oliver Trebilcock, Which? sound bar expert
Investing in a reliable dehumidifier means you can effectively tackle condensation, damp and mould. But before you click that 'buy' button, think about where the dehumidifier will sit in your home.
If you plan on using the dehumidifier in an unheated room, we suggest you go for a desiccant model. These use an absorbent material to extract the water from the air, a little bit like a sponge. Moisture generated from this process will drip into the water condenser.
However, if you're buying a dehumidifier for a heated room, pick a refrigerant model. These work by creating a cold surface. So when warm air comes into contact with the cold surface, this forms condensation and drips into the water tank. Don't buy a refrigerant and expect it to work in cool conditions.
Think about the size of your home, the extent of your damp problem and how many people are generating moisture in your home when deciding what size to buy.
When you're scrolling through tablet deals on Black Friday, make sure you consider how much internal storage each model offers.
Our tablet and TVs expert says:
'We suggest you avoid cheap tablets that you can only fit a few apps on, otherwise you'll be forced to buy an SD card to create extra space. If you're really unlucky, you'll end up buying a tablet that can only fit a single film on it.
'On the subject of cheap tablets, be aware that they often struggle to perform well. There are outliers but, typically, tablet quality and price go hand in hand and more expensive tablets do better.'
Martin Pratt, Which? tablet and TVs expert
Even on Black Friday, Dyson vacuum cleaner deals are far and few between.
We've found that Dyson models within the same range usually have the same core machine, with the only difference being bundled accessories and floor heads. If you're willing to pick up a new Dyson without some of those accessories, you could save yourself a tidy sum.
By contrast, we expect to see plenty of deals on Shark vacuum cleaners. So many, in fact, that we'll be sifting through the offers and picking out the deals genuinely worth your attention.
If you're shopping for a new dishwasher on Black Friday, try not to rush your decision - even if you spot a tempting discount.
Our dishwasher expert says:
'First, see if your current dishwasher can be repaired. If it really is nearing the end of its life, your next move is to pick out an efficient replacement.
'The difference between the most energy-hungry and energy-efficient full-sized dishwasher is £32 a year on your energy bills. This could easily add up to the cost of a whole new dishwasher over the course of its life.'
Aaron West, Which? dishwasher expert
Black Friday will undoubtedly bring with it a selection of offers on built-in ovens. When you're deciding which model to invest in, keep an eye out for the features that matter most.
Our built-in ovens expert says:
'Look out for ovens with high-temperature pyrolytic cleaning - we regularly find this to be the most effective type of self-cleaning. You might also want a model with telescopic shelf runners, as these make moving hot, heavy dishes in and out of the oven far less stressful.
'Finally, a temperature probe will help you to monitor whether your roast has reached the right internal temperature.'
Jane Darling, Which? built-in ovens expert
If you're choosing between these two gadgets, think about what features you really need before committing to a purchase, as this will help to determine whether you're better suited to a smartwatch or fitness tracker.
Our fitness tracker and smartwatch expert says:
'If you're not too fussed about smart features (such as checking the weather, making contactless payments, receiving texts and social media notifications) then you're probably better off with a fitness tracker. These tend to be cheaper and stick solely to health and fitness features above all else.
'But if you like the sound of smart features, a smartwatch will definitely be the better option - they're chunkier, more advanced and offer lots more functions.
'There's no hard-and-fast rule as to what you should spend on a wearable device. In fact, we've tested Best Buys costing as little as £30, and other high-scoring models costing almost £500.
Price tends to reflect features and appearance, rather than performance. So throwing more money at a purchase won't necessarily mean it's a good model.'
Rebecca Duff, Which? fitness tracker and smartwatch expert
Our expert reviews prove time and time again that spending more doesn't automatically ensure you'll bag a Which? Best Buy TV.
Our tablet and TVs expert says:
'Advanced HDR (Dolby Vision, HDR10+) isn't always used well and fancy screen types (QLED, NanoCell) aren't always better than ordinary LCD.
'Steer clear of store-brand TVs, too - those models often have features that match the big brands, but when we've tested them in our lab, they haven't been at the same standard.
Martin Pratt, Which? tablet and TVs expert
For printers, we've seen deals of 20% off or more in previous years, which really starts to adds up for the more expensive models. But you need to be careful when buying cheap printers.
Our printers expert says:
'We estimate that some inkjet printers cost as much as £100 a year in ink, while others, like some laser and ink-tank printers, can cost a few pounds to print the same amount.
'Over the lifetime of the printer, what looks like a bargain could cost you a lot more. We estimate this in all our expert printer reviews, so it's well worth a quick check before you buy.'
Felix Wilson, Which? printers expert