Using the CND Plexigel Builder is easy. First, make sure your nails are clean and dry. Then, apply the gel with the brush provided. You can use it over a tip or a sculpting form to create your desired length. For cracked nails, use the wearable patches to fill them. If your nails are broken, this product can repair them. When shaping flat nails, apply the gel to plump them up. As for maintenance, avoid exposing your nails to harsh chemicals for a long time. Also, don't use your nails as tools to prevent breakage. Keep your nails moisturized to maintain their health. If you notice any signs of irritation, stop using the product and consult a professional.