you'd have to give some sample pics to a groomer. i had one at petco and she was really nice---but she had no idea how to cut. WELL, she kept begging me to grow out sprites hair, and i said no, and to shave her. so that might've been my fault. and meet the groomer and talk to her, does she seem to like dogs? mine would look at every detail. she was like "sprite has a cut on her back, what is it from" (turned out it was because of a piece of metal sticking out from under the bed) and she was like "her hair is nice and soft, use this type of shampoo". stuff like that.
ask them if they use cotton in the ears and if you cant watch the first grooming session. i went to this place called Chow Bella, and it seemed like a nice place but they washed sprite and she had HUGE mats, like the size of kiwis on her side. and i saw how they were treating her and the groomer was brushing really hard and i was like "i want her now". then i take her and gruffi home--turns out that the little handkerchief that they put on gruffis neck was tight....and thats when i noticed the mats. she had like 3 or 4. i had to CUT THEM OUT. it would've been extremely painful for sprite if i brushed it(like that groomer) and she had bald spots. she didnt have mats like that before the groomer. ---anyway, that was my bad experience. the only reason i caught it was because i went early to pick the dogs up.
oh, my other bad experience--Precious Pets in Saugus...they gave sprite 2 ear infections! and gruffis hair looked burnt!!