1. go into the shops you are researching & talk with the groomer. Ask what the procedure is for grooming dogs. Some groomers/shops do what is called "cattle call" grooming which is where all the dogs come in at let's say between 8-9:30 & then given a time when to come back in the afternoon. Some book 2 dogs at a time & then in let's say 4 hours your dog is done. Some groomers groom 1 on 1 & call when done. Each one works for different clients.
2. Ask "how long they have groomed", what certification if any they have, do they attend grooming seminars or grooming shows, do they have pictures on the walls of their grooming etc.... Just because a groomer has groomed for 25 years doesn't make them a great groomer. Look for ones that continue their education in the grooming world, that attend trade shows etc...
3. Look at the cleanliness of shop, groomer, dogs etc... this to me does matter- do you want your groomer smoking while grooming your dog??? Do you want fleas on your dog when it leaves the shop??
4. Do you like the personality of your groomer? Some clash.
5. What is the waiting period to get your dog in to be groomed? Mine right now is 3 wks. Some groomers are booked 1 year in advanced & others aren't booked at all. Ask why?
These are some basic questions to ask your potential new groomer. Also, do they specialize in any particular breed. Mine is small dogs- poodles, yorkies, maltese, & shih tzu I see everyday & love working on them. I don't groom dogs over 30lbs.