Prior to the bath, you should groom your cat. Use a grooming glove, fine-toothed comb, or soft brush for shorthaired breeds and a wide-toothed comb and a soft slicker brush for longhaired breeds. Brush your cat thoroughly but gently, since the skin is thin and sensitive. Also, make sure to brush out any mats you may find - they are much harder to remove from wet hair. This is also a good time to check for sores, abscesses, lumps, and other skin problems. Clean your cat's ears and look for any excess wax or debris in the ears. You should also clip your cat's nails at this time. If your cat does not enjoy any of these procedures, wait until your cat has calmed down before starting the bath.
Assemble all the necessary materials (a soft towel, soft brush, and a shampoo and conditioner formulated especially for cats) before you get your cat. If the shampoo is very thick, you can dilute it with water before use. Just prior to the bath, if your cat allows, place cotton balls in the ears and apply an ophthalmic ointment to protect the eyes. Place a towel in the bottom of the sink or tub to prevent slipping. Be sure the "bathroom" is warm, and that your cat has a warm place in which to dry.
Keep in mind that cats do not like to be restrained; so the less it feels like you are controlling your cat, the better. Speak in soft tones and try to appear calm, since your cat will become more nervous if she senses you are apprehensive. Signs that your cat is anxious include flattening of the ears or whiskers, tail thumping, loud vocalizations, and open mouth panting.
Use lukewarm water. Cats generally dislike sprays, so it is often better to pour water over the cat rather than spraying. If you must spray, avoid hard sprays and spraying near your cat's face. You may want to wrap your cat in a thin towel and wet the coat through the towel, and then apply the shampoo. After shampooing, rinse your cat thoroughly. Rinsing is the most important step. You may need to rinse your cat twice to ensure that all soap is removed from the skin and coat.
Dry your cat gently with a towel. "Blotting" is better than rubbing, especially in longhaired breeds. Longhaired breeds will also benefit from an additional brush-out and time under a blow dryer on a no-heat setting (use only if your cat will tolerate the noise).
Remember, starting baths when your cat is still a kitten can help acclimate your cat to being bathed, making future baths faster, easier, and more comfortable for you and your cat.