The most reliable way to get Google reviews is to ask once in writing, immediately after the job is finished, with a direct link that takes a single tap. Asking in person almost never works, because people mean it and then forget in the car.

Put a QR code on the invoice or the receipt. It removes the hardest step, which is a customer finding your listing themselves on a phone while standing in a driveway.

Reply to every review you get, including the bad ones, and especially the bad ones. A calm reply to a complaint does more for the next customer reading than the complaint itself does against you. It is the clearest signal available that somebody is paying attention.