أرنسيا

Wet it, rub it between your palms to build a lather, then apply the lather — don't drag the bar across your skin. Stand it somewhere it can dry between uses, or it'll soften and go through twice as fast.

Morning, after cleansing, before sunscreen. If your skin is sensitive start every other day, and don't layer it with an exfoliating acid the same morning.

Not the same night. That combination is the single most common cause of irritation we hear about. Alternate nights and keep a soothing cream on hand.

It's South Korean. It's a small brand, so you won't find much about it online, and that puts people off. Worth trying if the solid-cleanser format appeals or you want a single-active concentrate without a long ingredient list. If you want the reassurance of a range everyone knows, Korean Skincare (K-Beauty) has the bigger names.