Flyin' Miata has had a YouTube channel since 2010 or maybe earlier. I'd put up random things of an idling V8 or some track footage or whatever. None of it got a lot of attention, although an engine start video of a straight-piped V8 got us the commission to build another one - so I guess that was a valuable one :) Another video of the same LS Miata doing an acceleration test (and chirping fourth) got passed around a fair bit. Both of those were just cellphone "let's capture this!" videos. Nothing's really gone viral.
In 2019, we hired Travis to take over the marketing and photography I'd been doing along with my other duties. One of the goals was to revitalize the channel. The best thing we did was start scheduling a weekly live broadcast. That forced us to make content and the nice thing about a live stream is that there's very little production overhead. We had some real duds - FM employees clowning around was NOT what people wanted to see - and started leaning more into our technical chops. Numbers started climbing.
Then 2020 happened. I took over the live videos, shooting from home using my phone and talking about a range of subjects from "car tours" to technical infodumps on various things. As things opened up again, Travis started holding the camera and we eventually got some of the other staff involved again in hosting. Those live shoots get some bumpers patched on and that's about it for editing.
Production values were pretty low during the solo days, but one of our most popular videos dates from then because it's just plain good info. Seriously, it's me standing in my shop talking about sway bars, with my iPhone SE ziptied to a transmission jack and lit by my shop lighting. Generally, as long as you have good sound people will tune in for the content. Our most popular videos seem to be installs, hard-core tech or listicles like "easy upgrades for any Miata".
We're now at just over 34k subscribers and it's 100% organic growth. We're not setting the world on fire, but we don't do anything to chase clicks. Our channel isn't monetized (at the moment) because it's advertising/brand building for the business. The tech videos, for example, are a slow burn. That sway bar video has a view count over time that's a straight slope, meaning just as many people are watching it today as there were in April 2020 when it was first published. But that means that people have spent 13,600 hours watching us be experts on sway bars.
TLDR: do regular live videos. They're an easy way to build a library and learn what your audience likes. They force you to get off the couch to keep your schedule. It'll keep you busy thinking of subjects, but if you don't have a deep pool of that you're never going to have a successful channel anyhow :) Live shoots also give you the chance to interact with your audience by responding to questions/comments, which means more engagement AND helps drive your direction. Don't stress production values/editing as much as decent sound and good content.
At the last couple of Miata shows I've attended, people don't walk up to me and say "I talked to you on the phone/forum/Facebook" or "I read your books and they were really helpful". Now it's all "I watch your videos on YouTube!" Weird.