Here's an excerpt from my Social Media Promotion For Musicians book that explains how to create the perfect thumbnail image in three steps.
"One of the easiest ways to get more views is by having an appealing thumbnail image.
When you upload a video, YouTube usually selects three screen grabs from which you can select the thumbnail. The problem is that it’s likely that none of these provide an image that instantly tells the potential viewer much about your video.
A customized image can now be used as the thumbnail instead of the selections made by YouTube or Vimeo. Here’s what to do:
2. Add text. Use an image editor like Photoshop, Pixelmator or GIMP to add text to identify the video. Make sure that the text is large enough to read easily on a small screen found on a smartphone. The file size should be less than 2MB.
3. Click on the Custom Thumbnail icon and upload. This can be found on the Info and Settings page, which is accessible from the first icon (the first one) at the bottom of the video viewer. Viewers will now see your custom thumbnail."
You can read more from Social Media Promotion For Musicians and my other books on the excerpt section of bobbyowsinski.com.