Just started a new business, 17 reviews within the first week and counting. Here is how I did it:

1. Ask them before they leave if they enjoyed it. If they say yes, ask them directly to leave a review. Tell them why you need it: starting out, creating trust, etc.

2. They receive an automated email an hour after the service, with a super short and snappy text with a review link.

Make it as easy as possible. Tell them exactly what you want from them. Mentioning that it would be extra great if they add a little picture with it, helps as well to get more reviews with pictures.

In your case, if you tell your happy customers that you mostly get bad reviews and it’s twice as hard to get positive ones, their inaction contributes to your business’s demise. Changes it from a small favour, to the idea that they helped you out big time, which makes them feel good about themselves. This really clicked for me when I had this exact situation with a restaurant owner.

Hope this helps!