Showing related posts or similar articles at the end of each post on your blog is a good idea. It help your readers to get more and Increase traffic to your blog. Rather than just showing links in related posts section, Showing an image thumbnail can grab readers attention more, because a picture is worth a thousand words. Try this beautiful widget on your blog to show related posts with thumbnails.

LinkWithin, a blog widget that shows related posts under each post, linking to Image thumbnail and post title as shown in the graphics. The widget is free and blends in with your site design. The widget links to stories that are relevant and interesting to readers of a particular post, keeping them engaged with your blog, and increasing your traffic.

No need to register, just enter your email, blog URl and select platform and select how many posts you want to put in related posts section and hit Get widget. The bad thing about this widget is, It shows related posts at the end of each post in home page of your blog too, But many bloggers want to just put related posts on post page or single page.