Testimonial sliders can be very handy on your website to display the great feedback you have received in the past from your visitors or customers.
The best way to create this on your website would be to use preset slider stacks made within Rocketspark. This is the most time-efficient way and you can customise the slider to match your branding. Here is How to Create and Edit a Carousel Slider Using a Preset Stack
Another way to display testimonials is by using the blog slider. This is a great way to display testimonials because you can link the slider to the article which you can use to go into greater detail and tell your customer's story about their awesome experience. Also if you use the blog for blogging purposes, you can use a blog tag like "Testimonial" and use that to link the blog slider.
Blog Slider - Displaying more than one blog post summary.