Just off-the-cuff thoughts.
1) Get a channel trailer for your homepage. In its two minutes, tell who you and what your channel is about.
2) The banner on your channel's homepage should visually tell what your channel's about.
3) If you're trying to go for two releases a day, release them at different times of the day to get YouTube's algorithm to reward you for doing so.
4) Add a postage stamp video of you in one of the corners. People subscribe to YouTubers, not channels.
Good luck!