Every beard starts with an idea.

Maybe it’s a vision of a full, rugged beard that frames the face, a neatly trimmed style that sharpens a professional look, or something in between. Getting to your desired beard often comes down to trimming, but experts say there isn’t one perfect method.

“There is no single medically ‘correct’ way to trim a beard,” said Dmitri Wall, a dermatologist and associate professor at University College Dublin, adding that some of the most commonly quoted “rules” around beards are grooming conventions, rather than medical directives.

How to trim a beard

Here’s what you need to know before you start.

“The main points are to use clean equipment, avoid repeatedly shaving too close in people prone to ingrown hairs and remember that trimming or shaving does not make hair grown back thicker,” Wall said. “It may look thicker temporarily because the hair shaft has been cut bluntly, but trimming does not change the follicle.”

Cleaning the beard is equally as important as shaving.

Wall suggested focusing less on washing the beard hair and more on washing the skin underneath. A gentle wash routine is usually sufficient for people with healthy skin, he said, though certain indicators like redness, or dandruff on the beard, scalp, eyebrows or chest, could require additional steps. An anti-dandruff shampoo once to twice weekly could help, but if the hair follicle is inflamed, Wall said it could be worth checking whether grooming tools like razors, clippers or ointments are perpetuating the problem.

“Greasier products can sometimes occlude follicles and worsen spots or pustules,” he said.

What is the two-finger rule?

A grooming technique, the two-finger rule generally helps decide where the lower beard neckline should sit: “roughly two fingers above the Adam’s apple in the midline, then curving gently upwards towards the angle of the jaw or bottom of the earlobe on each side,” said Wall. He added the technique is a simple visual guide to avoid shaving the neckline too high or low.

At the end of the day, grooming is important for visual appearances but issues can also be a sign of something deeper. Wall said a patchy beard or sideburn loss could be a sign of a scarring hair disorder, and added anyone with sudden, patchy, inflamed or scar-like loss of beard hair should consider seeing a dermatologist.