Google / Facebook / NextDoor / Yelp / Bing / etc.
There are several sites that people use to discover if they want to call you or do business with you, based upon your online reputation. You absolutely have to participate in the top 3, and likely need to address all of them eventually.
For each, you will need to solicit and encourage your clients and customers to leave a positive review on each of these platforms. You could simply request they leave an online review in an email that drives them to a page on your website that allows them to choose which platform to leave the review on, or you could send a link in the email that goes directly to the appropriate page online for the service you are targeting.
We suggest that we build a page on your website where you first ask them a question about being satisfied or dissatisfied with their interactions with your company. If they choose "dissatisfied" then you direct them to a form that is sent to you, so you can make it right, and not direct them to leave a review if they are not happy. if they choose "satisfied", then the next page could provide them the options to leave a positive review.