Eyebrows are not drawn, they are imitated. That is the sentence both specialists in this story use, and on its own it solves the most common problem with sparse brows - the pencil line that anyone can see from a distance has been drawn on.

"The trick is to imitate a hair, not to draw a brow," says Nuria Aluart, a beauty expert and founder of the Mumona brand. That means short, thin, separate strokes only where there is no hair, in the direction the hairs naturally grow, and in a matching tone - not a darker one.

Nuria Hernandez Marti, a lash and brow specialist and founder of a salon in Barcelona, starts from the step before. "Ideally you start from the natural brow and respect its structure," she says. In other words: analysing the face comes first, and the shape adapts to the person, not to the season's trend.

The order is what most people get wrong. First you comb, to see the real shape. Then you fill only the gaps with pencil. And finally you set it with gel. If the pencil comes before the comb, you end up filling places that were never empty.

The combing itself does more than it sounds like. Hernandez Marti advises brushing upwards at the start of the brow, then following the natural arch. Aluart adds that a gentle outward comb gives the greatest coverage, with a "flexible, slightly undone result" - a brow with movement, rather than a brow that just sits there.

For those where make-up does not solve it, there are longer-lasting procedures: lamination with tinting repositions the existing hairs and adds definition, while micropigmentation provides density that lasts. Microblading, henna and tinting are options that depend on how much hair there is and on skin type.

The products on lists like this are expensive as standard - a growth serum for 39 euros, a pencil for 36, a tinted gel for 35. That is over a hundred euros for three items, which is worth knowing before you start.