The reason why most "cinematic" efforts fail on youtube (even if art direction, lights, and exposure was right) is because they forget texture. That's where sony sensors don't do as well as arri or red out of the box. It's easy to get the negative film rendering with an arri, red or canon, but not as easy with a sony sensor. So you will have to use gaussian blur, or anamorphic lens blur plugins, or soften and sharpen plugins, in addition to color grading and grain. You need to get rid of the "thin" details of a 4k image and only allow the thick ones, as film did (there are various ways to do that).
As for color grading it needs to go towards deep, earthy, matte/neutral colors and contrast, not the high frequency rendering of colors that video cameras generate. Basically, you need to gun for a look that looks like a painting instead of a photograph. Unfortunately, there are no plugins for that on resolve, but it can be reproduced by hand. Or use the Look Designer plugin (not a lut), made by a colorist who has colored lots of shows for Netflix (a bit pricey subscription though).
Lastly, you need to crush AND lift your blacks. Watch any film movie, you will see that anything that is barely in shadow land, it quickly becomes black, without any detail on it. This is the opposite of how digital cameras shoot compared to film, which see better in the dark than in the highlights. That's why most DPs in Hollywood these days underexpose by 1 stop, to get better highlights ("highlights are king", they say). Do not be afraid of noise and don't denoise. You will bury that noise under grain and the softening plugins mentioned above anyway. So, you will need to crush your blacks using a curve, or LookDesigner's special CMY slider, and then you will have to lift it to about 30-50 IRE (so it's a creamy black, not all-black and contrasty). Most of the visible image needs to live in the midtones, No burned highlights (bring them down and give them an off white color), while shadows need to get all blacked out.
This is how film renders things, and how Hollywood grades their Alexa/RED footage too. This is not how most Youtube tutorials show how to do things though. They try to retain sharpness out of their sharp lenses and sharp sensors, most natural color, clean shadows, and they denoise the heck out of it. The result is a video look. The celluloid film look is instead soft (retains "thick" details only), often shot with vintage lenses that have character, it has earthy/neutral/matte/muted colors (just like traditional paintings do), great highlight retention, blacked out shadows, it's low contrast overall, and there's a buttload of grain. Buy some 1980-2000s rescanned 4k Blu-rays and study their look. I did so recently, after I canceled all my streaming subscriptions.
Modern film is closer to digital, as since Vision3, it has become much more accurate (and has lost some of its magic, IMHO). I'm personally more interested in the older look, since I grew up with 1980s films, like Predator, Terminator, and Star Wars. If you rather study modern Vision3 film look, consider the "Call me by your name" and "Good Times" blurays. On the first blu-ray, Call me by your name, you will see how much difference light can make too, compared to moody NY light on the second film. Mediterranean light has the best light in the world IMHO. Since I'm from there, I've seen lots of Mediterranean films (Italian, Spanish, Greek, Middle Eastern etc), and no matter how they were shot (on film, mostly in the 1990s when I still lived there), they had this magic light in them compared to ANY Hollywood film of the time. I haven't seen this magic light on any other non-Mediterranean film. It's also the reason why Game of Thrones was shooting in 3 different countries, for the various empires it was depicting. Light!
You might not like it, but it's the look I gunned for, and I liked the result:
BMPCC 4k, with Russian vintage lenses, anamorphic bokeh-modded, variable ND, IR CUT filter:
https://pbs.twimg.com/media/EiFL2dHU4AEJvoW?format=jpg&name=4096x4096https://pbs.twimg.com/media/EiFL2dHVoAAmpb8?format=jpg&name=4096x4096Sony A6400 (HLG3/rec709 + Look Designer 2.0), with Sigma 17-50mm f/2.8, variable ND:
https://pbs.twimg.com/media/EjSWpMFVkAADnXu?format=jpg&name=large
Illustration/collage artist now, music video filmmaker 10 years ago, programmer/tech journalist 20 years ago.