Foundations, primers and BB creams are some of the most important items of makeup. They create a base onto which other makeup can be applied and help to create an even skin tone.
The right ones can smooth away fine lines, banish dark circles and take years off our age. The wrong ones, however, can draw attention to problem areas and give our skin a muddy, artificial hue.
Last year it was all about the BB (blemish balm) cream. According to those in the know, the next big thing will be the CC (colour control) cream.
In theory, it should be a great thing that there are so many base layer products out there, but in reality it can be confusing. You certainly don't need to use them all - piling on unnecessary products will make no one look good — but what are all the options and how do you choose between them?
Let's start with BB creams. BB creams are worn alone or under make up. They typically work like a primer but also include sunscreen, a light tint and a moisturiser.
A CC cream is basically a new, improved BB cream. CC creams originated in Asia, where products designed to lighten and brighten skin are incredibly popular. Chanel launched a CC cream for the Asian market earlier this year, and there's a rumour that several other brands will launch CC creams for the UK market by the end of 2012.
In the UK, the sudden arrival of the BB cream eclipsed the growing popularity of traditional primers. But according to Chase Aston, international makeup artist at The Body Shop, while BB creams are often a great do-it-all product, those hoping to target specific areas will benefit from finding the right primer.
"Most BB creams are a one stop, all-in-one product," explains Chase.
"They smooth and prime the complexion, moisturise, hydrate, conceal and heal. The advantage of using a BB cream is that you forego the need to use a moisturiser, primer, foundation and in some cases concealer, as the BB formulations are designed as a one-stop, suits-all product.
"However, for medium to fuller coverage on blemishes and large open pores, a BB cream won't always be sufficient, and this is when I would recommend using a primer along with foundation."
[Related gallery: The ultimate BB cream guide]
Primers don't just cover up fine lines and enlarged pores: they'll give your makeup some serious staying power and generally prepare your skin for foundation.
"If your foundation tends to drag on application, appears patchy or starts to slip and slide after a few hours, then a primer is for you," says Chase.
"Using a primer will smooth the skin's surface, softening large pores and acting as an anchor between the skin and makeup, ensuring your make up looks good, feels good and lasts longer."
When it comes to foundation, less is more, especially in the case of powder. This type of foundation can be hard to carry off if you've got fine lines or enlarged pores, due to the powder's tendency to sink into these problem areas and draw attention to them.
However, there is an increasing number of powder foundations available which contain certain ingredients for creating the same flawless illusion associated with liquid ones. If possible, opt for loose powder foundations which contain plant silicones, which can smooth the skin while helping to keep it hydrated.
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If you're prone to oiliness, consider mineral foundations, which are especially effective at absorbing excess oil. Foundations containing salicylic acid are great for oily skin, due to the acid's ability to regulate the oil-producing glands which can cause spots.
The right shade
Which just leaves the issue of finding the right shade. Don't be afraid to ask for samples, and bear in mind that, in the same way perfume can smell very different once it's sprayed onto the skin, foundation can also change once it's been applied.
"Take three foundation shades as close to your skin tone as possible, draw three stripes side by side onto the cheek, jaw-line and neck and leave for a few moments," suggests Chase. "The shade that appears invisible on the complexion is the perfect shade for you.
Sarah McNamara Miracle Skin Transformer Face SPF20, £38, Miracle Skin Transformer
Clarins Skin Illusion Loose Powder Foundation, £28, House of Fraser
Le Teint Touche Éclat, £28, Selfridges
The Body Shop All-In-One BB Cream, £12, The Body Shop
Shiseido Radiant Lifting Foundation, £37, House of Fraser... coming 27 Sept 2012
Georgio Armani Maestro Complexion Perfector, £36, Selfridges
The Body Shop Skin Primer Moisture It, £11, The Body Shop