'No problem!" I think airily, when I get an invitation from beauty brand Prescriptives asking if I'd like to learn first-hand how they create their Custom Blend products, the most well-known of which is the bespoke foundation service.

The 'lipstick index' is off the mark in this recession and foundation has jumped to the fore, meaning make-up bases have never been more topical.

Having a tailor-made product whipped up, that's 100pc right for your skin type and tone, seems like just the ticket in an economic downturn, too.

While it costs a spendy €70, it's bound to save you cash in the long run -- I know I've got a drawer filled with discarded, useless products that just didn't suit in the cold light of day.

Products

The invite from the brand includes a teeny mention about taking a turn on their counter in Brown Thomas, too, but I don't pay that much notice at the time.

"Pah," I think, picturing myself in a crisp lab coat, stylishly blending beauty products, "how hard can it be?"

I begin to channel the inimitable Bridget Jones during her stint on fictional breakfast-TV show Sit Up Britain: "Will ace task in top, career-woman style, impressing all and sundry with fabulous skills." Oh dear. Famous last words.

Ahead of my stint on counter -- which, no, I can't get out of -- I report for training with Ailbhe O'Brien, Prescriptives' Irish Custom Blend ambassador. O'Brien makes it look oh-so-easy, but as she hands me a manual and patiently explains the process, it begins to sink in that this is not going to be cake walk.

In fact, it's pretty damn involved: there are recipes, pigments, twirly stirry things and bottles with calibrations on them that may as well be in Chinese, for all the sense they make to poor, confused, me. Oh, and I haven't even told you about Colorprint yet.

Colorprint is the step by which Custom Blend lives or dies, and I've quite simply got to get it right. If I can't correctly identify my customer's skin undertone (we're all either warm or cool, say the brand), then the foundation I mix will never be a match.

There's a categorisation system in place as well, organised into levels from one to seven, in cool and warm tones. But it quickly becomes apparent that to be really good at this, you need built-in, colour-theory smarts. O'Brien has The Knowledge, but me? I'm not so sure.

I dubiously decide that my pale face is a typical Irish milk bottle-type, though I'm barred from using that sort of language in front of the customers.

"You'd say 'cool rose'," laughs O'Brien, "it's much nicer!"

In Colorprint-language, 'milk bottle' translates into 'Level One Cool', and this is the guide I can use to begin to create my own Custom Blend foundation.

I check my manual, find the recipe that's right for me, and get blending. I'm bolstered up enough to get a little creative: the service allows for a lot more than camouflage and colour.

I can add some moisturiser, a luminising glow and anti-ageing benefits. I can even sheer the foundation out to create a summer-friendly tinted moisturiser.

Protocol

The day goes past way too quickly, and I leave clutching my churning, worried stomach and my training manual filled with advice, recipes and protocol. Yes. Protocol.

I'm reminded that I'll have to mind my Ps and Qs, wear something ironed, brush my hair and behave all day long.

For someone who works from home and frequently wears their jammies 'til noon, this might turn out to be the hardest task of all.

I report bright and early for duty. A potter around the counter familiarises me with what-goes-where, and then I meet a customer who's waiting for a Colorprint analysis.

I assess my victim as a Level Two Warm -- and amazingly, I'm right. Out comes my recipe book and I ask my customer a few questions about her skin type and her particular concerns.

This lady wants a bit of luminosity and some extra moisturiser in her base, if you please, and as I faux-expertly blend, we chit-chat about holidays, the weather and what's good in the sales.

I'm getting the hang of this! Then I'm done and I'm testing the foundation on her skin. A few minor adjustments are all that's required and I send my customer off happy.

Reassured by Ailbhe O'Brien that I managed to acquit myself, I leave footsore but happy.

Custom Blend foundation costs €70. In addition, Custom Blend lipgloss, powder, concealer and tinted moisturiser products are all available at the Prescriptives counter at Brown Thomas, Dublin and you can also avail of the service at House of Fraser, Dundrum

- Kirstie McDermot