I have a friend who runs a youtube make up channel. She’s been doing pretty well. My number one suggestion is once you post a video, repost it to facebook, and then individually contact as many of your friends as you can trust and ask them to watch the video. A lot of the “popularity” of a youtuber is based on the number of views. My friend, when she started would send me a link every time she posted saying literally “I know you don’t do make up, but if you could just watch my new video, put it on mute whatever in the background. That would be a huge help.”
Other things she did is she uses multiple platforms for each post. Posts pics to instagram, and link the video, post to facebook, she runs a twitch account streaming video games, etc. She also works at a Sephora, so she would use her platforms to let people know when there were deals at the store.
The first step is to get the views, post often, keep it short (most people will click off if the first 10–30 seconds aren’t engaging enough). My friend usually starts her videos with the final product pictured, then goes back to the beginning.
Good luck!