What is the best way to caulk a bathtub yourself?

Start by removing all old caulk using a caulk remover tool or utility knife, then clean the surface thoroughly with rubbing alcohol or a mildew-killing cleaner and let it dry completely. Fill the tub with water before caulking so the tub is weighted down, which prevents the caulk from cracking later when weight is applied. Apply painter's tape along both edges of the joint to get a clean line. Use a silicone or siliconized latex caulk designed for bathrooms, cut the tube tip at a 45-degree angle, and apply a steady bead in one continuous motion. Smooth it with a wet finger or caulk tool, remove the tape immediately, and let it cure fully before using the tub, usually 24 hours.