If you're making videos, you want people to see them. So what is the best way to get people to watch your videos? It's by making videos they want to watch.
Now you might make something that you think is amazing and everybody should see, but if other people are not interested in the topic, the niche or the video then they won't watch it.
So you need to make something that they want to see instead of making what you want to show them. Now how do you do this?
Go to Google and type in something to do with your niche. For instance if you have a channel about knitting, type in 'how to knit'. Google will now give you a bunch of suggestions on what you might be searching for based on what other people have searched for. This is a great way to come up with some topics that apparently people want information on. Now try not to pick the most obvious things that are at the top, cause chances are a lot of videos exist on this topic already. Get creative with your searches and see what you can come up with.
Try not to make videos about topics that have hundreds of videos on the same topic already. If there is too much competition it's going to be tough to get your video viewed.
A great tool that is free to use, but also has a paid version if you want some more options, is Tubebuddy. One of their features is the keyword finder. You can use this to type in a keyword or phrase and the keyword finder will tell you how it will rank on YouTube. Plus a big bonus here is that on the side it will give you related keyword ideas that could spark a great idea for a video. Tubebuddy works as an integration on YouTube with Chrome and really is a great tool to use for any YouTuber.
Look at your competition, go to their channel and see what kind of videos they make, what they have made in the past and how certain topics have done for them. You can see over time which videos got the most views and that way you can figure out what type of videos drives the most viewers to their channel. I'm not saying copy them and make the same videos, but use this knowledge and learn what your audience wants to see and try and make that type of content.