To understand YouTube's algorithm, you have to understand your audience.
YouTube's search and discovery system aim to help viewers find the videos that they want to watch and to maximize long-term viewer engagement and satisfaction.
The algorithm follows the audience. Pay attention to what your viewers watch and don't watch, what they watch the most, and what they skip. If you focus on what your audience likes, the algorithm will follow.
Discovery optimization tips
Use titles thumbnails that accurately represent your content.
Videos are less likely to be recommended to new viewers if the titles and thumbnails are misleading, clickbaity, or sensational.
Use creative video techniques to keep your audience engaged.
Effective editing can maintain and build your viewers' interest throughout the video.
Organizing the content on your channel can build long watch time sessions.
Using a series playlist allows other videos in the playlist to be featured and recommended when someone is viewing a video in the series.
Create a regular release schedule for your videos when uploading.
Review your YouTube Analytics to see where your views are coming from and which videos are successful at keeping viewers watching.