Thumbnails

Thumbnails are what grab peoples attention and get them interested. Creating a good thumbnail is always a hard thing to do. As times change so does thumbnails and the way to get attention. The best practice is to have a few thumbnails so you can change it if you are not getting the reaction that you wanted. Mr Beast the most viewed Youtuber has also mentioned doing this. Netflix also has multiple thumbnails to test the target audience engagement.

On the right you can see that changing a thumbnail later can spike your views and create more growth off a video you already made.