Every pet has their back story of what makes them scared or nervous.  I see this situation 7 times a day if not more.  The goal is to try to make grooming easy and quick for them.  A helpful tip is to remain calm and confident yet gentle and keep the drop off quick.  The longer you stay in the lobby the more intense the trembling and anxiety can escalate requiring longer for your pup to settle its nerves after you leave.  97% of the time, once the owner leaves the pet is no longer trembling and is restoring its sense of calm.  Of course, if your pet is making you feel that the groomer or the situation is not ok, listen to your pet and continue your search for another groomer.  The goal is to make it pleasant for you both and if the owner is not ok then your pup won’t be ok either.  They feed off our nerves, stress, emotions, or energy which has many shapes in our daily lives.