I've taken Gabby (yorkie-poo) to Wags to Whiskers in Long Beach twice and have been happy both times. The first time was just a bath with a puppy trim. The last time I had her hair cut shorter, down to 1/2 inch. I was happy with the results. I also gave my friend a gift certificate as a gift when she babysat Gabby for us. She took her yorkie there and was happy with them.
Here is their website:
Wags to Whiskers Pet Grooming in Long Beach - Because we love pets!
good luck!