You have to make interesting thumbnails and titles, also you should make the first 15 sec catchy enough that the viewer will stay there you youtube will recommend it to more people. Your niche should be interesting too, or if the niche not then yourself.
Here is how I would do it:
-Pay for someone to make the thumbnails
OR
make 100 or more thumbnails, it does not have to be your video, just make it for other videos and see if it is good enough, just screenshot the main page of youtube and replace your thumbnail there with another video (also change the title), and then ask some of your friends if they would click on it. Simpler is some times just more, keep that in mind, sometimes 2 layers could be enough for a thumbnail with a red circle.
The title should raise questions in a viewer like HOW did he do it, WHAT did he do etc. Also make it short or mid length, don't make it too long otherwise it won't be visible to the viewer.
So,
The thumbnail and the title should:
- raise a question
- be attention-grabbing
- be “clickbaity”
- be shocking
+ For the tags try to optimize your tags, put as many as possible where you have good chance that you will be the first recommendation.