Clean the tile surrounding the area to be caulked with water and mild soap. Allow the area to dry completely.
Cut the tip off the caulking cartridge at a slight slant. However, place the cut a little farther down on the cartridge if you need a thicker line of caulk.
Place the cartridge into the caulking gun.
Press the tip of the cartridge into the joint you're filling, and use the gun to release the caulk as you move the gun along the joint.
Wet your finger with water and use it to smooth out the caulk.
Apply soap and water to a soft cloth, and wipe down any excess caulk before it has a chance to dry. Wait at least one full day before you expose the caulk to water.