I ask for them.  I provide the link and make it as easy as possible for them. 

Article is general and not useful, "ask for them," well we knew that ...  

What platform do you want the reviews to show on?

I think you need to be more granular. 

Do you want reviews on your website that you control thus they are all 5 stars?

Do you want to pay for reviews at yelp / zillow/ google/manta/angie's 

or pay a company like hubspot/feefo/yotpo/reefo/trustpilot...

thousands of them

Ask them right after you hand them the keys to the home. They are still on that feel good vibe are still excited about you and hopefully felt good about the process. I usually recommend sending homeowners an automated email marketing message with a link to a review funnel that simply asks something to the effect of "Did I do a good job, are you happy?" YES or NO, if they select yes, I drop them off on a review portal and I rotate which one I send them to, Yelp, Facebook, Google, BBB, etc. If they select NO, I direct them to a contact form so they can tell me what went sideways and that way you mitigate complaints from showing up in review websites. Hope this helps. I don't want to tip my hand too much, but I specialize in reputation management and can help you generate more positive reviews for your business if that is something you are focused on.

First, do a good job to deserve one. Ask at closing or around closing when everyone should be happy to get the deal done.

I have started using G only for reviews. I think they are most effective there but it just takes time to get the ball rolling. 

It's also hard to ask clients who already left a few say years ago, to do it on another platform. I really think Z is on the decline. There was a survey that buyers liked Redfin's site better. That makes a review on Z less effective in my book.

I used to have a service & everyone took the easy way out with stars. I forgot that I could move those I guess ???? duh.

Asking for them right before or the day after close of escrow. I just got two more doing it that way.

Reviews are important for those considering doing business with you.

These new customers, looking to buy or sell a house, have 5 important questions to which they seek answers.
When an existing event reveals a solution delivered for on if those 5 questions, I ask for 'commment/review' for that solution only.  At the end I amy have 5 comments specific to the new customer reality.

"Annette make me feel as though I was the only person that mattered on the planet. Her cell kept buzzing but her attention was only on me.  I don't know how she does it because every time I CALLED she answered. Amazing!"  -Robert T.
What 'real' question does the above comment answer?

it's my wife's company and I help out as needed.  So I always just ask them to post a review on Google for the company.  That keeps her busy, which keeps me busy.

trial and error and do what is working at the time.

To make it easy for my customers, I have a notification bar at the top of each page on my website. It says Please leave a Customer Review. Thank you! with a link to my Google review page.

I remind customers to please click the link to leave a review.

On my blog posts, it says Please leave a Blog Review. Thank you! with a link to my Google review page.

Sometimes I get a good review from a blog reader for providing useful content in a blog post, even if I do not make a sale.

Sometimes I get phone calls asking for information for their research. If  I spend time answering their questions, I will ask them to please leave a Thank You for your time review.

I have the most Google reviews for any notary in my state.

I have found that calling and asking and then following up w/ an email right away that has the link to leave the review works best.Make it easy for them.

Calls, Text, Emails, Snail Mail, Rince & Repeat.

We have a standard email that we send to clients once a transaction has closed. Still, not all will post. Like lead generation, it takes quantity to find quality.