More bows!!
Brush and check for tangles right before her bath.
Shampoo and condition the same way you would your own hair. Rinse out shampoo well before applying conditioner.
When you are working in the shampoo, do not rub the hair in circles. Use your fingertips to massage the body and work the shampoo more in straight down motion.
After the bath, wrap a towel around her and hold her for a few minutes. Do not rub her hair with the towel. You can also let her run around. Lots of Yorkies love to do zoomies after a bath. Do not be surprised if she rubs her head.
Use a hairdryer on low heat to dry. Hold the dryer a safe distance away and keep the airstream moving, not concentrated on one spot, at all times.
Use your fingers to run through her hair while drying. Don't force a brush or fine tooth comb through wet hair. That will cause breakage.
Once she is thoroughly dry, brush and comb thoroughly.