Eyeliner is the single most transformative make-up product of them all. You might feel reliant on foundation, or think no beauty statement screams as loudly as a red lip, but hear me out. Eyeliner dictates the mood of your make-up. Take a simple, natural-looking make-up, add a cat eye, and the face becomes instantly polished, clean. Take the same make-up look but add a grubby streak of almost blotted, lived-in liner, and the overall effect becomes grungy and cool. Regardless of what the eyeshadow is or isn’t doing, it is the liner that sets the tone of the eyes, and consequently the whole face. By changing your liner, you can update the rest of your make-up.
So how do you know which liner to use, and when? It depends on your preference, but generally, for blendability and a smoky eye, I'll choose a buttery kohl liner such as Charlotte Tilbury Rock 'n' Kohl in Bedroom Black (€25 at charlottetilbury.com) for two reasons. First, it gives the soft, wafting edges that are desirable in a smoky eye (hard lines are its ruination) but it also makes a perfect base for powder eyeshadow.
The new Nars High-Pigment Longwear Liner (€24 at Arnotts) in Via Veneto will do the job beautifully too. If you're feeling adventurous, it comes in a rainbow of shades, but black liner is beauty bread and butter. Without the powder applied on top, soft liner may crease and drift. The powder sets it and is enhanced by the depth. Try applying a jewel tone like a jade or amethyst over a black kohl base – it's positively explosive.
If you are an eye make-up adventurer (I follow the broadcaster Louise McSharry on Instagram in part because of her constantly evolving eye make-up), then you may like a hybrid. The new Huda Beauty Life Liner (€23.95 at Brown Thomas) has liquid on one end and a pencil on the other. It promises 48-hour wear and is black as a priest's socks, so have an oil or balm make-up remover in the house or you may find yourself trying to cry it off your eyes. Whether you're in the mood for a smoked-out look or a sharp liquid liner, this will give you either in an instant.
I love and wear liquid liner, and though I should at this point have shares in Chanel for all the raving I have done about their Signature de Chanel liner (€40 at Brown Thomas and Debenhams), it is in my opinion the absolute best. Before I found it, I happily used a Maybelline Eye Studio Lasting Drama Gel Liner (€11.99 at Boots) for years, but the Chanel, with its bristled brush and ink cartridge, is simply superior to anything else for creating a cat eye. The Maybelline comes in a pot and requires slightly more application skill. However, I'll be honest: only two things can guarantee a good eyeliner flick. One is a lot of practice and dedication. The other is hiring a professional make-up artist.