Before you create your thumbnail, you should know the ideal thumbnail size and dimension. YouTube recommends that the thumbnail size should be 1280 pixels wide by 720 pixels tall. Your image should have a minimum width of 640 pixels, and an aspect ratio of 16:9.

This is the most obvious, but important part of your thumbnail. A great photo attracts the attention of your viewer. You should use a high-quality still image from your video that acts as a teaser. Consider using a close-up shot of a face, preferably one where you’re making “eye contact” with the viewer.

If you don't intend to use human faces on your thumbnail, you should not bother about capturing an emotional image for your thumbnail. Instead, you should use a custom graphic that sums up all the benefits of your video.

Adding a title text in your YouTube thumbnail like the image above holds many benefits. The biggest one being, it gives your viewers more context about the video.

Avoid using clickbait images or titles that could hurt your brand. You should keep your creativity in check and only provide a thumbnail image that benefits you, not harm you.

According to YouTube, 90% of the best performing videos on YouTube use Custom thumbnails. And these custom thumbnails are made from easy and professional thumbnail makers