Start promoting videos with known people and ask them to like and subscribe your videos.
Distribute your videos on other social media platforms.
Facebook will never show link, so it ia better to upload the Video accordingly.
Send videos to the right audience, because they will watch videos till the end and there’s when You Tube will deem whether your video is preferred or not.
At the end of video, have your call to action, as in Like or Subscribe the videos.
Cross promote and collaborate with other You Tubers. However, don’t spam them.
If you are writing a Blog, kindly include the link of your videos at the end. Likewise, don’t spam the videos of other bloggers.