Opdateret: 13. juli 2020
Here are the banner template files I talked about in the video.
Use this download link or click the folder icon below to get a ZIP-file containing a PSD with all the images collected in one single file, or download the below PNG's separately. Remember to download the full-resolution file. It might help to copy the images' URLs and paste them into a new tab before saving them.
Banner preview ONLY
Texted guide (found on https://support.google.com/youtube/answer/2972003?hl=en)