The true test of customer service comes when a complaint is received. Relationship marketing doesn't mean that each customer has to be your new best friend. It does mean, however, that you develop an individualized rapport with each client. It means you care enough to refer them to someone else, as appropriate, and call to see how it's going. And, it means honestly evaluating your abilities and personality, as well as the handler and the dog, each time you sign up a new client.
Momentum is built on one success at a time.
Get the ball rolling in your training group. Step back and look at yourself, and your trainers, from a client's perspective. Have you built up a referral network for problems outside your area of expertise - and no one is an expert in everything. You'll never lose customers because of good customer service. You'll never have clients walk off the field because you praised their efforts.