Step-by-step instructions:
Step #1: Place your Shih Tzu in the tub and once they are settled, wet the entire body.
A nozzle works best. If you do not have a nozzle, a small cup or bowl can work, though it may not be as effective. Be sure that the coat is thoroughly soak down to the skin.
Step #2: Shampoo your Shih Tzu.
Do not be shy with the shampoo; it’s important to use enough to thoroughly clean the entire body. Scrub and massage the shampoo down through the coat to the skin. Go over every area other than the face (legs, paws, back, chest, neck, underbelly, armpits, tail, bum).
Note that the order of this does not matter, but if your Shih Tzu has a particular area that they do not like having touched (like the tail or the paws) do that area last.
Step #3: Clean your Shih Tzu's face with one of the washcloths.
Dip the washcloth into the sudsy water, wring it out a bit, and then gently swipe over the face, making sure to clean very well around the eye area. Swipe over the face as many times as necessary to ensure all tiny food bits or debris particles are cleansed away. Once this is done, use the second washcloth to dry around the eyes.
Step #4: Once you are done with the face, gently clean the genital area, using the washcloth.
Step #5: Rinse the shampoo out.
It is important to rinse very well. Even if you are using a superior shampoo, it is meant to do its job and then be removed. Any residue will prevent the conditioner from doing its job. Once you think you have rinsed it all away, rinse the coat for an additional minute.
Step #6: Now it's time to condition the coat.
If you don't use a conditioner, you're only doing half the job; it's vital for good coat health. During the shampooing process, hair cuticles open. A wash-out conditioner helps smooth them back down. Otherwise, the coat can be extremely vulnerable to contact friction, arid air, and more.
Apply a generous amount to the coat (or to your hands first) and take your time massaging this into the coat, reaching every area and being sure to work it down to the hair tips. Once it's applied, leave it on for a full 5 minutes. You can keep massaging lightly or just allow your Shih Tzu's coat to soak it up.
Step #7: Rinse out the conditioner. Note that you may need to drain some water out before you add more in while doing this. Also, you do not need to, nor should you, go overboard with rinsing the conditioner out. Leaving perhaps 5% or so still in the coat, to be transferred to a towel, is just fine and can actually help protect the coat if the towel happens to be less than ideal in regard to softness.
Step #8: Remove your Shih Tzu from the bath into a quality towel.
Carefully remove your Shih Tzu from the tub, place them down into the center of a towel, allow them to shake, and then gently wrap them up. Do not rub the coat, the goal will be to pat them dry (more ahead) before air-drying or blow-drying.