Learn how to create a proper Google review link so that your customer lands directly on the Google Business reviews star selection screen. Delivering your customer directly to the star selctor is a sure way to secure that 5 star review.
Always ask the customer at the end of the job: "Would you mind if I send you a request for feedback on how I did today?".
Be sure to spell your customers name correctly and with the correct capitalization (IE. Susan Geoffrey NOT susan jeffrey).
Sending your review request as soon as possible while the great experience is still fresh in the customers mind.