I've always kinda let my thumbnails and videos speak for themselves. I've never wanted to be "known" but rather, I've wanted people to be interested in my art, so I've simply tried to present my art in the best way possible through thumbnails and video. My videos could be improved a lot, but even before I was focusing on keyword best practices, I feel my thumbnails were always solid enough to get some basic attention.
For me, it was a case of having the right topic (dinosaurs, pretty evergreen) my passion (art, evergreen) and time (Jurassic World release) so the mix just meant I had to make the right videos that were popular enough with the right audience around the Jurassic World release. So I focused on drawing dinosaurs from the trailer, the trailers and film release were pretty big, my thumbnails basically showed you what you were going to get, and the titles were straight to the point, which ended up being searchable enough that people found them and watched, so I didn't have to do a huge amount.
Anyone who's known me for any amount of time knows I love dinosaurs and art, so I made a reputation for myself, and the evergreen nature of my channel did the rest. I didn't even really need to advertise, I was just discovered organically through time.
So never underestimate the power of a good thumbnail and a topic that is interesting to the right people who share your passion. And for the love of all that's good, don't just do something because you hope you'll get views. The more you do something just for the views, the more of a chore it will feel like, and the more disappointment you'll feel when you don't get the results you expected. I just do what I enjoy, it doesn't always get me the views I hope for, but I enjoy the craft of drawing and sharing my art, so any views I do get is a bonus.
Over time my knowledge about analytics, what to look for in analytics, and learning keyword strategies has been improving. My titles and topics are what I'm not focusing on this year, and how to interpret the data better.