Creating a thumbnail image in Figma is really easy. You just need an appropriate canvas size, required images and desired colors selection. We will apply the background color to canvas and then we will use text, colors and shapes.
After uploading your video, YouTube auto generates video thumbnail. But you may not want to use auto generated thumbnail. In that case, you can create your own custom thumbnail and upload it with video. It is recommended that, you use a thumbnail of at least, 1280 by 720 pixels in width and height for youtube videos.