Once you have a review you'll want to be able to manage and respond to them, bearing in mind that sellers with over a 3.5-star rating are two and half times more likely to get hired.
You can see all your reviews at the bottom of the reviews section under 'Your Reviews'.
To reply to a review just press 'Respond' and type your response in the pop-up.
You'll then want to see what this will look like to customers so, head back to the 'Profile' tab (you should see your completion percentage has now also gone up) and click 'View Profile as Buyer sees it'.
This is how the buyer will see it: