Cosmetic rollers at home, sensibly
A cosmetic roller is a surface tool. Treated as one, it is straightforward. Treated as a clinical device, it is not, and the distinction is worth understanding before you buy either.
Keep it clean and keep it yours
Rinse the head, let it dry, and do not share it. This is the single most important habit and the one most often skipped.
Light pressure only
More pressure does not do more. It irritates skin and leaves it looking worse for a day, which is the opposite of the point.
When to leave it alone
Broken skin, sunburn, an active breakout in the area, or any skin condition you are being treated for. If you are under a dermatologist for something, ask them first rather than asking a product page.