Ah. I used his videos to help me through all 3 calculus courses. Quite helpful. To think that a couple of minutes from him helped me better than hours of classes with university professors

.
Did you try
YouTube Academy? Me neither. This is a post from someone who has never ever published in YouTube, but with comments regarding what I would do if I were to make content for YouTube.
Video: Never have I ever made a video for YouTube, but if your budget allows it, get a good camera. If it were me (and I'm not you

), I'd get a
Mirorless 60fps camera. Make the video such that if there is ever a wide panorama, it is blurred and the focus is on the part of interest. That makes it so much easy on the eyes of the viewer as involuntarily the mind focuses on the sharp crystal clear parts. For example look at
this video. See how pleasant it was the image of the cat while at the bicycle? The background was blurred and the cat looked crystal clear despite the YouTube's 480p downgraded resolution. You can even see the cat's whiskers with exalted detail.
Edit: He has in the video description the camera he used on the video. It's a mirrorless one. And the lens too is in the description. I died when I saw the price

.
Audio: Get a good microphone. If needed, edit the audio to remove background noise. Make sure that whatever algorithm is used in audio editing can be repeated for uniform results across your videos.
Content: Regarding the content, I always looked up after videos that went straight to the point. No dubstep intros, or any other intro for that matter. A second or two seconds greeting characteristic of you should be enough. Students like tutors that go straight to the point. Intros are annoying and undesirable. Not to mention they consume bandwidth from data plans (in case they are accessing it through a cellphone) and tablets or cellphones make it hard to navigate the video accurately.
Preparation: I cannot put enough emphasis on this. Preparation is key. Master the exercise you will show how to solve. In my opinion transitions are okay if they don't happen in all your videos, but let the viewer know that a transition occurred by saying for example: "You probably just saw a small transition. I had a little problem with these numbers, but we are back..." and then you continue. Or "I just had my epic/weird cat calling me at the door, but we are back...

" You know, stuff like that. Older adults won't like that kind of talk. They'll say it's unprofessional, etc. But honestly, if your target is the younger, they probably won't mind. They might even like it and gain interest in your cat and ask you questions and videos from it. Comments like: "Show us you cat!" It's up to you to be dead serious or a good sport

. Transitions that happen through video effects take more time than spoken transitions and sometimes it is annoying to see special video effects on the video.
Finally, all in all, pretty much all YouTubers beg for likes. I have always disliked that practice. I've always found it of very bad taste to ask for likes. But that's up to you. If it were me, I wouldn't ask for likes or ask anyone to subscribe. I would take my feedback from the comments, not based on likes/dislikes or subscriptions. However, reality is that I have seen that those who don't ask for likes or subscriptions, rarely get any likes or subscriptions. People pass from them. I will never understand that, but those have been my observations.