YouTube search is optimised for time watched which means you need to really understand what works and what doesn't work in the production of videos in terms of audience retention. Not only do you need to focus on the SEO side of your videos but you need to investigate your analytics and see how long viewers watch your creations. Do they start to drop off noticeably after 30 seconds into a 2 minute clip? This could indicate you need to make shorter videos.
Both Google and YouTube rank videos in search partially on their ability to retain an audience and how that video contributes to a viewer's overall viewing session on YouTube.
Your YouTube analytics can be found on the left hand side of your channel. Go and check them out to see what you can learn to improve your videos.
Tip: A good rule of thumb is to aim to maintain over 60% of your audience straight to the end of your videos, where they’ll encounter your call to action. Make adjustments if your video statistics indicates lower performance.